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0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems: An Infomercial Michael Malisoff, Roy P. Daniels Professor of Mathematics Louisiana State University JOINT WITH ENGINEERING AND MATHEMATICS COLLEAGUES AND STUDENTS SPONSORED BY NSF/ECCS/EPAS AND NSF/CMMI/SDC PROGRAMS Applied Analysis Seminar LSU Department of Mathematics November 17, 2014 Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

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Page 1: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

013

Designs and Theory for State-ConstrainedNonlinear Feedback Controls forDelay Systems An Infomercial

Michael Malisoff Roy P Daniels Professor of MathematicsLouisiana State University

JOINT WITH ENGINEERING AND MATHEMATICS COLLEAGUES AND STUDENTS

SPONSORED BY NSFECCSEPAS AND NSFCMMISDC PROGRAMS

Applied Analysis SeminarLSU Department of Mathematics

November 17 2014

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

113

Collaborators Fumin Zhang from Georgia Tech and Miroslav Krstic (MK) from UCSDCurrent PhD Students Ruzhou Yang Ningshi Yao

Total 3-Year Budget $871000 (LSU Portion $380928)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn

We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function u

The functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty

D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ)

Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 2: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

113

Collaborators Fumin Zhang from Georgia Tech and Miroslav Krstic (MK) from UCSDCurrent PhD Students Ruzhou Yang Ningshi Yao

Total 3-Year Budget $871000 (LSU Portion $380928)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn

We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function u

The functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty

D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ)

Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 3: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn

We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function u

The functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty

D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ)

Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 4: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn

We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function u

The functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty

D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ)

Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 5: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn

We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function u

The functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty

D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ)

Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 6: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function u

The functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty

D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ)

Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 7: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty

D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ)

Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 8: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ)

Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 9: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ)

Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 10: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 11: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

213

What Do We Mean By Delayed Control Systems

These are doubly parameterized families of ODEs of the form

Y prime(t) = F(t Y (t)u(t Y (t minus τ)) δ(t)

) Y (t) isin Y (1)

Y sube Rn We have freedom to choose the control function uThe functions δ [0infin)rarr D represent uncertainty D sube Rm

Yt (θ) = Y (t + θ) Specify u to get a singly parameterized family

Y prime(t) = G(t Yt δ(t)) Y (t) isin Y (2)

where G(t Yt d) = F(t Y (t)u(t Y (t minus τ))d)

Typically we construct u such that all trajectories of (2) for allpossible choices of δ satisfy some control objective

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 12: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 13: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

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313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 15: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 16: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded

γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 17: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 18: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 19: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 20: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

313

What is One Possible Control Objective

Input-to-state stability generalizes global asymptotic stability

Y prime(t) = G(t Yt ) Y (t) isin Y (Σ)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)(UGAS)

Our γi rsquos are 0 at 0 strictly increasing and unbounded γi isin Kinfin

Y prime(t) = G(t Yt δ(t)

) Y (t) isin Y (Σpert)

|Y (t)| le γ1(et0minustγ2(|Yt0 |[minusτ0])

)+ γ2(|δ|[t0t]) (ISS)

Find γi rsquos by building certain LKFs for Y prime(t) = G(t Yt 0)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 21: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 22: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 23: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn)

and2 d

dt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 24: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

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413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example

The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 26: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D

Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 27: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 28: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

413

What is a Lyapunov-Krasovskii Functional (LKF)

Definition We call V ] an ISS-LKF for Y prime(t) = G(t Yt δ(t))provided there exist functions γi isin Kinfin such that

1 γ1(|φ(0)|) le V ](t φ) le γ2(|φ|[minusτ0])for all (t φ) isin [0+infin)times C([minusτ0]Rn) and

2 ddt

[V ](t Yt )

]le minusγ3(V ](t Yt )) + γ4(|δ(t)|)

along all trajectories of the system

Example The function V (Y ) = 12 |Y |

2 is an ISS-LKF forY prime(t) = minusY (t) + 1

4Y (t) + δ(t) for any D Fix τ gt 0

V ](Yt ) = V (Y (t)) + 14

int ttminusτ |Y (`)|2d`+ 1

int ttminusτ

[int ts |Y (r)|2dr

]ds

is an ISS-LKF for Y prime(t) = minusY (t) + 14Y (t minus τ) + δ(t)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 29: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 30: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 31: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 32: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 33: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 34: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

513

Background on NMES Rehabilitation

It artificially stimulates skeletal muscles to restore functionalityin human limbs (CragoJezernikKoo-LeonessaLevy-Mizrahi)

It entails voltage excitation of skin or implanted electrodes toproduce muscle contraction joint torque and motion

Delays in muscle response come from finite propagation ofchemical ions synaptic transmission delays and other causes

Delay compensating controllers have realized some trackingobjectives including use on humans (Dixon Sharma 2011)

Our new control only needs sampled observations allows anydelay and tracks position and velocity under a state constraint

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 35: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

513

NMES on Leg Extension Machine

(Loading Video)

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

AN14NMESVidmov
Media File (videoquicktime)

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 36: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

513

NMES on Leg Extension Machine

Leg extension machine at Warren Dixonrsquos NCR Lab at U of FL

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 37: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 38: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delay

A =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 39: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 40: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 41: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 42: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

613

Mathematical ModelMI (q)︷︸︸︷Jq +

Mv (q)︷ ︸︸ ︷b1q + b2 tanh (b3q) +

Me(q)︷ ︸︸ ︷k1qeminusk2q + k3 tan (q)

+Mgl sin (q)︸ ︷︷ ︸Mg (q)

= A (q q) v (t minus τ) q isin (minusπ2

π2 )

(3)

J andM are inertia and mass of the lower limbmachine thebi rsquos and ki rsquos are positive damping and elastic constantsrespectively l is the distance between the knee joint and thecenter of the mass of the lower limbmachine τ gt 0 is a delayA =scaled moment arm v = voltage potential control

q(t) = minusdFdq (q(t))minus H(q(t)) + G(q(t) q(t))v(t minus τ) (4)

qd (t) = minusdFdq (qd (t))minus H(qd (t)) + G(qd (t) qd (t))vd (t minus τ) (5)

max||qd ||infin ||vd ||infin ||vd ||infin ltinfin and ||qd ||infin lt π2 (6)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 43: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i

where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 44: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi

The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 45: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

713

Voltage Potential Controller

v(t) = g2(ζd (t+τ))vd (t)minusg1(ζd (t+τ)+ξ(t))+g1(ζd (t+τ))minus(1+micro2)ξ1(t)minus2microξ2(t)g2(ζd (t+τ)+ξ(t))

for all t isin [Ti Ti+1] and each i where

g1(x) = minus(1 + x21 )dF

dq (tanminus1(x1)) +2x1x2

21+x2

1minus (1 + x2

1 )H(

x21+x2

1

)

g2(x) = (1 + x21 )G

(tanminus1(x1) x2

1+x21

)

ζd (t) = (ζ1d (t) ζ2d (t)) =(

tan(qd (t)) qd (t)cos2(qd (t))

)

ξ1(t) = eminusmicro(tminusTi )

(ξ2(Ti) + microξ1(Ti)) sin(t minus Ti)

+ ξ1(Ti) cos(t minus Ti)

ξ2(t) = eminusmicro(tminusTi )minus(microξ2(Ti) + (1 + micro2)ξ1(Ti)

)sin(t minus Ti)

+ ξ2(Ti) cos(t minus Ti)

and ξ(Ti) = zNi The time-varying Euler iterations zk at eachtime Ti use measurements (q(Ti) q(Ti))

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 46: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

713

Voltage Potential Controller (continued)

Euler iterations used for control

zk+1 = Ω(Ti + khi hi zk v) for k = 0 Ni minus 1 where

z0 =

(tan (q(Ti))minus tan (qd (Ti))

q(Ti )cos2(q(Ti ))

minus qd (Ti )cos2(qd (Ti ))

) hi = τ

Ni

and Ω [0+infin)2 times R2 rarr R2 is defined by

Ω(T h x v) =

[Ω1(T h x v)Ω2(T h x v)

](7)

and the formulas

Ω1(T h x v) = x1 + hx2 and

Ω2(T h x v) = x2 + ζ2d (T ) +int T+h

T g1(ζd (s)+x)ds

+int T+h

T g2 (ζd (s)+x) v(s minus τ)ds minus ζ2d (T +h)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 47: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

813

NMES Theorem (IK MM MK Ruzhou IJRNC)

For all positive constants τ and r there exist a locally boundedfunction N a constant ω isin (0 micro2) and a locally Lipschitzfunction C satisfying C(0) = 0 such that For all sample timesTi in [0infin) such that supige0 (Ti+1 minus Ti) le r and each initialcondition the solution (q(t) q(t) v(t)) with

Ni = N(∣∣∣(tan(q(Ti)) q(Ti )

cos2(q(Ti ))

)minus ζd (Ti)

∣∣∣+||v minus vd ||[Timinusτ Ti ]

) (8)

satisfies|q(t)minus qd (t)|+ |q(t)minus qd (t)|+ ||v minus vd ||[tminusτ t]

le eminusωtC(|q(0)minusqd (0)|+|q(0)minusqd (0)|

cos2(q(0)) + ||v0 minus vd ||[minusτ 0])

for all t ge 0

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 48: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 49: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 50: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 51: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

913

First Simulation

Jq + b1q + b2 tanh (b3q) + k1qeminusk2q + k3 tan (q)

+Mgl sin (q) = A (q q) v (t minus τ) q isin (minusπ2

π2 )

(9)

τ = 007s A(q q) = aeminus2q2sin(q) + b

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(10)

qd (t) =π

8sin(t) (1minus exp (minus8t)) rad (11)

q(0) = 05 rad q(0) = 0 rads v(t) = 0 on [minus0070)Ni = N = 10 and Ti+1 minus Ti = 0014s and micro = 2

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 52: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

913

First Simulation

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 53: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 54: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 55: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 56: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1013

Simulated Robustness Test

We took τ = 007s and the same model parameters

J = 039 kg-m2rad b1 = 06 kg-m2(rad-s) a = 0058b2 = 01 kg-m2(rad-s) b3 = 50 srad b = 00284k1 = 79 kg-m2(rad-s2) k2 = 1681radk3 = 117 kg-m2(rad-s2) M = 438 kg l = 0248 m

(12)

qd (t) =π

3(1minus exp (minus3t)) rad (13)

q(0) = π18 q(0) = v0(t) = 0 Ni = N = 10 Ti+1 minus Ti = 0014

We used these mismatched parameters in the control

J prime = 125J bprime1 = 12b1 bprime2 = 09b2 aprime = 1185abprime3 = 085b3 k prime1 = 11k1 k prime2 = 0912k2 bprime = 098bk prime3 = 09k3 Mprime = 097M and l prime = 1013l

(14)

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 57: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1013

Simulated Robustness Test

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 58: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 59: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 60: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 61: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 62: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 63: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 64: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1113

Summary of NMES Research

NMES is an important emerging technology that can helprehabilitate patients with motor neuron disorders

It produces difficult tracking control problems that containdelays state constraints and uncertainties

Our new sampled predictive control design overcame thesechallenges and can track a large class of reference trajectories

By incorporating the state constraint on the knee position ourcontrol can help ensure patient safety for any input delay value

Our control used a new numerical solution approximationmethod that covers many other time-varying models

In future work we hope to apply input-to-state stability to betterunderstand the effects of uncertainties under state constraints

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 65: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 66: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 67: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 68: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

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1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

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1213

Openings for PhD Students

I have openings for PhD students that each pay up to $22000per school year plus a tuition remission plus certain travel

One would be co-advised by Miroslav Krstic Daniel L AlspachEndowed Chair in Dynamic Systems and Control at UCSD

Miroslav and I are studying time delayed state constrainedordinary and hyperbolic PDEs using predictive controls

Potential engineering applications include laser pulse shapingNMES and slugging in oil production

Even though my projects are sponsored by NSF Engineeringyou do not need any engineering background to be considered

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

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1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

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1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 73: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 74: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 75: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1313

Openings for PhD Students (contrsquod)

I also have at least one opening on my joint project with FuminZhang from Georgia Tech ECE on a totally different topic

Fumin is a rising star who won an ONR YIP Award a LockheedInspirational Young Faculty Award and an NSF CAREER grant

Our project is on model predictive control which is an excitingmix of controls and optimization on a receding time horizon

Fumin and I are developing a new timing model to help resolvecontentions on computer networks eg in cars

It uses event-triggered controls and robust forward invarianceto help determine how much uncertainty a system can tolerate

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays

Page 76: Designs and Theory for State-Constrained Nonlinear ...malisoff/papers/17Nov2014AAS.pdf · 0/13 Designs and Theory for State-Constrained Nonlinear Feedback Controls for Delay Systems:

1313

Openings for PhD Students (contrsquod)

malisofflsuedu 225-578-6714

Malisoff (LSU) and his Colleagues and Students State-Constrained Nonlinear Feedback Controls with Delays