biomechatronics - lecture 12. artificial motor control i

BiomechatronicsDelft University of Technology

Course 2006-2007(Wb 2432)

Frans van der Helm

Lecture 13Artificial motion control

Contents• Artificial motor control

– Full artificial control– Modulation of natural control system

• Model of human controller– stability analyis– limitations and adaptation

• Supervisory control situations– supervisor over automated control loops

artificial motor control

artificial motor control interacts with physiological control

Reflexivecontrol

Artificialmotorcontrol

Physiologicalfeedforward

control

reflexcontroller

Controlsignals

assistive concepts

Sensorysignals

1.Take over

control

2.influencingbehaviour

control system

3.training

reflexcontroller

Controlsignals

Sensorysignals

1.Take over

control

assistive concepts

Bionic gloveDr. Prochaska, Edmonton

Take over control

Cleveland FES Center

stimRRD: Dr. Hermens

Dr. KenneyDr. Nene

UT: Ing. BulstraDr. HolsheimerVerloop

MST: Dr. v.d. AaDr. Buschman

2 channel stimulator for drop foot

Take over control

Take over control

FES for complete spinal cord lesion

reflexcontroller

Controlsignals

Sensorysignals

2.influencingbehaviour

Control system

assistive concepts

Influencing behaviour control system

Parkinson patient

Dr. Lenders, MSTMedtronic

Brain stimulationwith Parkinson

Dr. Holsheimer, UT

Influencing sensationSpinal cord stimulation

against pain

Influencing behaviour control system

stim

reflexcontroller

attenuationhypersensitive reflexesby reciprocal inhibition

Influencing behaviour control system

Spasticity calf muscle

The problemCVApatient

t (s)0.0 1.0

200

ϕ(deg)

SoleusEMG (uV)

200

-20

ϕ(deg/s)

.

0

0

0

Ankle

stim

reflexcontroller

Shank front Shank back

Influencing behaviour control systemattenuation

hypersensitive reflexesby reciprocal inhibition

100

Vm

stretch only

-0.2 0 0.2 0.4time [s]

stimulation + stretch

200 d

eg/s

soleus EMG

angular velocity0 200

0

150

0 2002

9

v [deg/s]v [deg/s]

soleus EMG Moment

mea

n m

omen

t [N

m]

peak

str

etch

ref

lex

EM

G [

µV]

no stimulation

stimulation

no stimulation

stimulation

results

Influencing behaviour control systemAttenuation hypersensitive reflexes

by reciprocal inhibition

0 2 5 0 5 0 0 7 5 0

0

1 0 0

2 0 0

3 0 0

Stimulation

no stimulation

.ϕ (deg/s)

EM

G (u

V)

During walking

(Voormolen et al, 2000)

Stimulationand stretchduring initialswing phaseof gait

Experiments were performed at Aalborg University

Spinalcontroller

delay

stretchsensors

stimϕ (deg/s)

EM

G (u

V)

artificial motor controlHierarchical control

Assistive system Human body

Intention detectionand sensory feedback

to the user

Conscious motorplanning and sensing

Task coordinationMotor coordination

andsensory integration

Low levelactuator control

Muscle controlwith proprioceptive

feedback

artificial motor controluser interaction

continuous operator control

intention detection

Artificialreflex

Impedancecontrol

High level

Low level

Continuouscontrol

Discretetime control

Assistive system Human body Intention detection

and sensory feedbackto the user

Conscious motorplanning and sensing

Task coordinationMotor coordination

andsensory integration

Low levelactuator control

Muscle controlwith proprioceptive

feedback

continuous operator control

intention detection

Artificialreflex

Impedancecontrol

High level

Low level

Continuouscontrol

Discretetime control

standing

sitting

Standing(right legin front)

Standing(left legin front)

standup

Step right

standup

Step left

Finite state control

artificial motor control

Principle Control a relation betweenposition and force

K

continuous operator control

intention detection

Artificialreflex

Impedancecontrol

High level

Low level

Continuouscontrol

Discretetime control

Fy

yr

r ky = F + ky

F

yr y

y

FZ C

Plant+

loadFr

yr

artificial motor controlPhysiological Impedance control

of the human body

Crago et al., CWRU

Control of FES assisted

hand grasp

MIT, Hogan, Krebs

artificial motor controlartificial Impedance control

of assistive system

Impedance controlled systemfor standing-up training

(Kamnik & Bajd, Ljubljana)

Physical Therapy

Lokomat system

LOPES

LOPES

BLEEX

HAL5

HAL5