Industrial IoT Motor Control Trajectory Optimization

Randall Restle Digi-Key Electronics

1

2

• Requirements

• Rediscovery

• The Missing Link

• The Case for SoC

3

Industrial IoT Motion Controller Requirements

• Connection to the Internet

• A communications payload that fits that medium

TCP

t t

4

Where There Is More Time

COMM. BW PROGRAM CONTROL SOURCES

LOW 1. Move Sequencing

2. Profile Generation

3. Trajectory Update

4. Position Loop Existing Altera® Motor

Control Library

5. Velocity Loop

6. Commutation

7. Current Loop

8. Power Switching

HIGH 9. Torque/Force Motor

Splitting the Intelligence in a Motion Control System by: Curtis S. Wilson - 1992 Motion Control Magazine

5

Infinite # of Ways to Go from A to B but One is Best

Gradual and

Smooth

Snappy and

Abrupt

6

• Requirements

• Rediscovery

• The Missing Link

• The Case for SoC

7

Mechanical Engineers Solved this in the 1950s

Stoddart, David A. “Polydyne Cam Design,” Machine Design (January 1953), 121.

Kloomok, M. and Muffley, R. V. “Plate Cam Design,” Product Engineering (February 1955), 156.

8

Popular Solutions of Electrical Engineers

POSITION

TRAPEZOIDAL

VELOCITY

ACCELERATION

S-CURVE SPLINE

A1

A1 + A2

A1 + A2 + A3

A1 A2 A3

9

D D D Dwell D D R D D F D R D modified sine rise D R R 3-4-5 half rise start D R F 8th order rise start D F D modified sine fall D F R 8th order fall start D F F 3-4-5 half fall start R D D R D R R D F R R D 3-4-5 half rise end R R R constant velocity rise R R F half harmonic rise end R F D 8th order fall end R F R full harmonic fall R F F half harmonic fall start F D D F D R F D F F R D 8th order rise end F R R half harmonic rise start F R F Full harmonic rise F F D 3-4-5 half fall end F F R half harmonic fall end F F F constant velocity fall

8th Order Rise Start

8th Order Fall End

8th Order Fall Start

8th Order Rise End

CAM SEGMENT TYPES

See KLOOMOK & MUFFLEY 1955 for like types

18 Classical Cam Shapes

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18 Classical Cam Shapes KLOOMOK & MUFFLEY 1955

Segment Names CAM SEGMENT TYPES

See KLOOMOK & MUFFLEY 1955 for like types

D D D Dwell D D R D D F D R D modified sine rise D R R 3-4-5 half rise start D R F 8th order rise start D F D modified sine fall D F R 8th order fall start D F F 3-4-5 half fall start R D D R D R R D F R R D 3-4-5 half rise end R R R constant velocity rise R R F half harmonic rise end R F D 8th order fall end R F R full harmonic fall R F F half harmonic fall start F D D F D R F D F F R D 8th order rise end F R R half harmonic rise start F R F Full harmonic rise F F D 3-4-5 half fall end F F R half harmonic fall end F F F constant velocity fall

3-4-5 Half Rise Start

3-4-5 Half Fall Start

3-4-5 Half Fall End

3-4-5 Half Rise End

11

18 Classical Cam Shapes KLOOMOK & MUFFLEY 1955

Segment Names

KLOOMOK & MUFFLEY 1955

Segment Names

D D D Dwell D D R D D F D R D modified sine rise D R R 3-4-5 half rise start D R F 8th order rise start D F D modified sine fall D F R 8th order fall start D F F 3-4-5 half fall start R D D R D R R D F R R D 3-4-5 half rise end R R R constant velocity rise R R F half harmonic rise end R F D 8th order fall end R F R full harmonic fall R F F half harmonic fall start F D D F D R F D F F R D 8th order rise end F R R half harmonic rise start F R F Full harmonic rise F F D 3-4-5 half fall end F F R half harmonic fall end F F F constant velocity fall

Half Harmonic Rise Start

Half Harmonic Rise End

Half Harmonic Fall Start

Half Harmonic Fall End

CAM SEGMENT TYPES

See KLOOMOK & MUFFLEY 1955 for like types

12

18 Classical Cam Shapes KLOOMOK & MUFFLEY 1955

Segment Names

KLOOMOK & MUFFLEY 1955

Segment Names

D D D Dwell D D R D D F D R D modified sine rise D R R 3-4-5 half rise start D R F 8th order rise start D F D modified sine fall D F R 8th order fall start D F F 3-4-5 half fall start R D D R D R R D F R R D 3-4-5 half rise end R R R constant velocity rise R R F half harmonic rise end R F D 8th order fall end R F R full harmonic fall R F F half harmonic fall start F D D F D R F D F F R D 8th order rise end F R R half harmonic rise start F R F Full harmonic rise F F D 3-4-5 half fall end F F R half harmonic fall end F F F constant velocity fall

Modified Sine Rise

Constant Velocity Rise

Constant Velocity Fall

Modified Sine Fall

CAM SEGMENT TYPES

See KLOOMOK & MUFFLEY 1955 for like types

13

18 Classical Cam Shapes KLOOMOK & MUFFLEY 1955

Segment Names Full Harmonic

Rise Full Harmonic

Fall

KLOOMOK & MUFFLEY 1955

Segment Names

KLOOMOK & MUFFLEY 1955

Segment Names

D D D Dwell D D R D D F D R D modified sine rise D R R 3-4-5 half rise start D R F 8th order rise start D F D modified sine fall D F R 8th order fall start D F F 3-4-5 half fall start R D D R D R R D F R R D 3-4-5 half rise end R R R constant velocity rise R R F half harmonic rise end R F D 8th order fall end R F R full harmonic fall R F F half harmonic fall start F D D F D R F D F F R D 8th order rise end F R R half harmonic rise start F R F Full harmonic rise F F D 3-4-5 half fall end F F R half harmonic fall end F F F constant velocity fall

CAM SEGMENT TYPES

See KLOOMOK & MUFFLEY 1955 for like types

14

Elegance of the Mechanical Solution

Precision Points POSITION

D R F R D F D

[ 8th Order Rise Start ] [ Full Harmonic Fall ]

VELOCITY

ACCELERATION

Motion becomes fluid

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• Requirements

• Rediscovery

• The Missing Link

• The Case for SoC

16

7th Order Polynomial

𝒑(𝒙) = 𝑨𝒙𝟕 + 𝑩𝒙𝟔 + 𝑪𝒙𝟓 +𝑫𝒙𝟒 + 𝑬𝒙𝟑 + 𝑭𝒙𝟐 + 𝑮𝒙 + 𝑯

𝒗(𝒙) = 𝟕𝑨𝒙𝟔 + 𝟔𝑩𝒙𝟓 + 𝟓𝑪𝒙𝟒 +𝟒𝑫𝒙𝟑 + 𝟑𝑬𝒙𝟐 + 𝟐𝑭𝒙 + 𝑮

𝒂(𝒙) = 𝟒𝟐𝑨𝒙𝟓 + 𝟑𝟎𝑩𝒙𝟒 + 𝟐𝟎𝑪𝒙𝟑 +𝟏𝟐𝑫𝒙𝟐 + 𝟔𝑬𝒙 + 𝟐𝑭

𝒋(𝒙) = 𝟐𝟏𝟎𝑨𝒙𝟒 + 𝟏𝟐𝟎𝑩𝒙𝟑 + 𝟔𝟎𝑪𝒙𝟐 +𝟐𝟒𝑫𝒙 + 𝟔𝑬

𝑝0 = 𝐻

𝑣0 = 𝐺

𝑎0 = 2𝐹

𝑗0 = 6𝐸

𝑝1 = 𝐴 + 𝐵 + 𝐶 + 𝐷 + 𝑗0 6 + 𝑎0 2 + 𝑣0 + 𝑝0

𝑣1 = 7𝐴 + 6𝐵 + 5𝐶 + 4𝐷 + 𝑗0 2 + 𝑎0 + 𝑣0

𝑎1 = 42𝐴 + 30𝐵 + 20𝐶 + 12𝐷 + 𝑗0 + 𝑎0

𝑗1 = 210𝐴 + 120𝐵 + 60𝐶 + 24𝐷 + 𝑗0

Explicit specification of the boundary conditions:

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Challenge of Speed is Met with FPGA Fabric

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Challenge of Arithmetic Variety is Met with a mP

𝐴 =−20(𝑝1 − 𝑝0)

𝑥7+10 𝑣1 + 𝑣0

𝑥6+−2 𝑎1 − 𝑎0

𝑥5+𝑗1 + 𝑗06𝑥4

𝐵 =70(𝑝1 − 𝑝0)

𝑥6+−34𝑣1 − 36𝑣0

𝑥5+13𝑎1 − 15𝑎0

2𝑥4+−3𝑗1 − 4𝑗0

6𝑥3

𝐶 =−84(𝑝1 − 𝑝0)

𝑥5+39𝑣1 + 45𝑣0

𝑥4+−7𝑎1 + 10𝑎0

𝑥3+𝑗1 + 2𝑗02𝑥2

𝐷 =35(𝑝1 − 𝑝0)

𝑥4+−15𝑣1 − 20𝑣0

𝑥3+5𝑎1 − 10𝑎0

2𝑥2+−𝑗1 − 4𝑗0

6𝑥

Closed Form Expression for the Coefficients

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Python*-based 7th Order Polynomial Class

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DSP Builder Model

21

• Requirements

• Rediscovery

• The Missing Link

• The Case for SoC

22

A Complete Solution

COMM. BW PROGRAM CONTROL SOURCES

DEVICES

LOW 1. Move Sequencing Polynomial

Cam Generator

ARM 2. Profile Generation

3. Trajectory Update

FPGA

4. Position Loop

Existing Altera® Motor

Control Library

5. Velocity Loop

6. Commutation

7. Current Loop

8. Power Switching

HIGH 9. Torque/Force Motor Motor

Intel® SoC FPGA

Splitting the Intelligence in a Motion Control System by: Curtis S. Wilson – 1992 Motion Control Magazine

23

This is Why Intel® SoC FPGA

DHCP SNMP HTTP FTP TFTP

UDP TCP

ICMP

IP

ARP

Ethernet

𝒑 = 𝑨𝒙𝟕 + 𝑩𝒙𝟔 + 𝑪𝒙𝟓 + 𝑫𝒙𝟒 + 𝑬𝒙𝟓 + 𝑭𝒙𝟓 + 𝑮𝒙𝟓 +𝑯

High-Performance CPU High-Performance FPGA

Better Motion Control

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Summary and Next Steps

• Industrial IoT (IIoT) Motion Control requires reducing communications bandwidth

• What was not feasible in the 1950s is feasible now with SoCs

- This problem has been solved

• Current solutions are not optimum

• SoC makes possible:

- Sophisticated motion control

- Internet communication

- Robust application framework built on Linux

• New and better machines are possible

- Faster, smoother, less maintenance, flexible, larger

- More energy efficient and cost effective