Design of a Simulink-Based Control Workstation for Mobile ...ee.bradley.edu/.../venom/deliverables/progress_presentation2.pdf · Design of a Simulink-Based Control Workstation for

Design of a Simulink-Based Control

Workstation for Mobile Wheeled Vehicles with

Variable-Velocity Differential Motor Drives

Kevin Block, Timothy De Pasion, Benjamin Roos, Alexander SchmidtGary Dempsey

Bradley University Electrical and Computer Engineering Department

March 1, 2016

Presentation Outline

•Background•Benjamin Roos•Timothy De Pasion•Alexander Schmidt•Kevin Block•Conclusion

2

Overview

What: Design and Implement Control Workstation with a Model-Based PID Controller that has Feed-Forward Compensation

How: Combination Simulink and Experimental Platform

Why: Future Control Algorithm Research, Development, and Testing at Bradley University

3

Objectives

•Simulink System Integration Complete

•Controller Development Complete

•Controller Code Written

•Experimental Platform Integration Complete

•Simulink GUI Complete

•System Integration in Progress

•System Testing in Progress

4

Division of Labor

5

TABLE I. DIVISION OF LABORTask Name Team Member Name

Simulink Integration Timothy De Pasion

Controller Development Benjamin Roos

Controller Code Kevin Block

Experimental Platform Integration Benjamin, Kevin, Timothy

Simulink GUI Alexander, Timothy

System Integration All Team Members

System TestingAlexander, Benjamin,

Timothy

Fig. 1 – Division of Labor

Overview

6Fig. 2 – High Level Block Diagram

Experimental Platform

7

Fig. 3 – Experimental Platform Block Diagram

Simulink System

8

Fig. 4 – Simulink System Block Diagram

Overall Gantt Chart

9

Fig. 5 – Team Gantt Chart



10


•Background•Benjamin Roos

•Controller Development – PI Feedback Controller•Controller Specification Verification•Current Source and Dynamic Model Matching

•Timothy De Pasion•Alexander Schmidt•Kevin Block•Conclusion

11

Vehicle Plant Bode Diagram

12Fig. 6 – Vehicle Plant Bode Diagram

Vehicle Plant Root Locus

13Fig. 7 – Vehicle Plant Root Locus

Plant and Controller Root Locus

14Fig.8– Vehicle and Controller Root Locus with Zero at s = -19.5 rad/s

Controller and Plant Bode Diagram

15Fig. 9 – Continuous Vehicle and Controller Bode with Controller Gain = 500

Discrete PI Controller Step Response

16Fig. 10 – Complete Controller Response to Worst Case Conditions,

Settling Time = 1 second





17

Disturbance Rejection Specification

•The drive control system shall minimize the effect of external torque disturbances.

•Performance Specification:•Shaft RPM change of less than or equal to 40%

•Test Measurements:•Max Instantaneous Error of 35.75% at 20 RPM•Spec has been met for the Simulink Model

18

Disturbance Rejection Specification

19Fig. 11 – Disturbance Response Curves with Disturbance Change at 2 seconds

Step Tracking Specification

•The drive control system shall reduce vehicle tracking errors for step commands.

•Performance Specification: •Average difference between input and output of less than or equal to 20% over 4 seconds

•Test Measurements:•Max Error is about 14% at 400 RPM•Spec has been met for the Simulink Model

20


21Fig. 12 – Average Error of Step Responses

Ramp Tracking Specification

•The drive control system shall reduce vehicle tracking errors for ramp commands.

•Performance Specification: Average difference between input and output of less than or equal to 20% over 4 seconds

•Test Measurements:•Max Error is about 35% at 400 RPM/s

22


23Fig. 13 – Average Error for Ramp Responses


24Fig. 14 – Ramp Response Curve with a Ramp Input = 400 RPM/s

Parabolic Tracking Specification

•The drive control system shall reduce vehicle tracking errors for parabolic commands.

•Performance Specification: Average difference between input and output of less than or equal to 40% over 4 seconds

•Test Measurements:•Max Error is about 20% at 400 RPM/s^2

25


26Fig. 15 – Average Error for Parabolic Responses





27

Current Source Torque Disturbance Matching

28

Fig. 16 – The Experimental Platform Disturbance Input should match that of the Simulink Model

Plant Inertia Differences Between Systems

•Simulink Vehicle and Motor Inertia:𝐽 = 5.28 ∙ 10−3 𝑘𝑔 𝑚2

•Experimental Platform Motor and Generator Inertia:𝐽 = 6.12 ∙ 10−6 𝑘𝑔 𝑚2

•Goal: Match Acceleration Based on𝑇𝑆𝐼𝑀𝐽𝑆𝐼𝑀

=𝑇𝐸𝑋𝑃𝐽𝐸𝑋𝑃

= 𝑎

𝑇 = 𝑁𝑒𝑡 𝑇𝑜𝑟𝑞𝑢𝑒𝐽 = 𝑀𝑜𝑚𝑒𝑛𝑡 𝑜𝑓 𝐼𝑛𝑒𝑟𝑡𝑖𝑎

𝑎 = 𝑟𝑜𝑡𝑎𝑡𝑖𝑜𝑛𝑎𝑙 𝑎𝑐𝑐𝑒𝑙𝑒𝑟𝑎𝑡𝑖𝑜𝑛

29



30


•Background•Benjamin Roos•Timothy De Pasion

•Simulink Integration•Controller Development – Feed Forward•Terrain Creation•GUI Creation

•Alexander Schmidt•Kevin Block•Conclusion

31

Simulink System

32

Fig. 17 – Simulink System Block Diagram

Simulink Integration

•Goal: Combine individual Simulink models into one overall model

•Problems: •Timing Problems•Model Redesign

33

Simulink Integration: Timing Problems

34Fig. 18 – Simulation Time Improvement

Simulink Integration: Model Redesign

Rotary Encoder

35Fig. 19 – Rotary Encoder Simulink Model

Simulink Integration: Final Simulink Model

36Fig. 20 – Final Simulink System





37

Controller Development – Feed Forward

•Specifications•40% Overshoot•2 Second Settling Time

•Used a digital redesign method to create the transfer function

38

3250.3 ∗ 1 0.9986 − 𝑧−1

1 0.6667 + 𝑧−1

Ts=0.001 seconds

Eq. 38-1

Controller Development – Feed Forward

•Simulink System

39Fig. 21 – Simulink Controller

Feed Forward Controller Performance

40Fig. 22 – Step Response with and without Feed Forward

Feed Forward Controller Performance

41Fig. 23 – Zoomed in Step Response

Feed Forward Controller: Error

42Fig. 24 – Error with and without Feed Forward





43

Terrain Creation

•Involved writing MATLAB scripts to test both the Simulink Model and the Experimental Platform•Circle Test•Straight line no elevation•Straight Line with Elevation•Worst Case•Best Case•Random•Ramp

44



•Simulink Integration•Controller Development – Feed Forward•Experimental Platform Integration•Terrain Creation•GUI Creation


45

Overview

46Fig. 25 – High Level Block Diagram

GUI Creation

•Stop Button•Start Button•Select or Create a Test•Choose Surface•Add a Payload•Change Gravity•Use an Ideal Vehicle•Change Motor Parameters

•Best and Worse Case

•Simulink/Experimental Platform Selection

47

GUI Creation

48Fig. 26 – GUI

GUI Creation: Start\Stop Button

49Fig. 27 – Start\Stop GUI

GUI Creation: Create Test

50Fig. 28 – Create Test in GUI

GUI Creation: Choose Surface

51Fig. 29 – Choosing a Surface Fig. 30 – Drop Down Menu

GUI Creation: Set Test

52

Fig. 31 – Setting a Test in the GUI

GUI Creation: Add a Payload, Change Gravity, Ideal Vehicle

53

Fig. 32 – Changing values in the GUI

GUI Creation: Change Motor Parameters

54

Fig. 33 – Changing Motor Parameters

GUI Creation: Choose Between Systems

55

Fig. 34 – Choose Between Systems in the GUI



56


•Background•Benjamin Roos•Timothy De Pasion•Alexander Schmidt

• Motor Thermals• H-Bridge• GUI Design

•Kevin Block•Conclusion

57

Motor Thermals: 4 Sources of Heat

•Resistance in the windings

•Coulomb Friction

•Viscous Friction

•Dynamic Loads

58

Resistance in the Windings

•I2*R Losses

59

Fig. 35 – Top Level Resistance Power Loss

Fig. 36 – Bottom Level Resistance Power Loss

Viscous, Coulomb, and Dynamic Loads

•V*T Losses

60

Fig. 37 – Coulomb Friction Losses

Fig. 39 – Dynamic Load Losses

Fig. 38 – Viscous Friction Losses

Total Power Loss

61

Fig. 40 – Top Level Power Loss Simulink Block

No Load Values

62Fig. 41 – No Load Thermal Measurement

Loaded Values

63Fig. 42 – Loaded Thermal Measurement





64

H-Bridge Build

65

Fig. 43 – Laboratory H-Bridge Setup

H-Bridge Build

66

Fig. 44 – H-Bridge Pinout

“LMD1820 3A, 55V H-Bridge” National Semiconductor, Dec. 1999.

H-Bridge Thermals

•Total Power of H-BridgePTotal = PQ + PCOND + PSW [EQ – 67.1]

PQ = Quiescent Power Dissipation

PCOND = Conductive Power Dissipation

PSW = Switching Power Dissipation

67

Quiescent Power Dissipation

PQ = IS * VCC [EQ – 68.1]

IS = Quiescent Current

VCC = Supply Voltage

68

Conductive Power Dissipation

PCOND = 2 * I2RMS * RDS (ON) [EQ – 69.1]

IRMS = RMS Current

RDS (ON) = On Resistance of the Power Switch

69

Switching Power Dissipation

PSW = (EON + EOFF) * F [EQ – 70.1]

EON = Turn On Energy

EOFF = Turn Off Energy

F = Switching Frequency

70

H-Bridge Total Power

•Using Equations 67.1 – 70.1

PTotal = 0.6[W] + 2.7[W] + 0.3 [W]

•Maximum power dissipation of the H-Bridge without a heat sink is 3.0 Watts

•PTotal = 3.6 Watts

•Heat Sink is Required!

71





72

GUI

73Fig. 45 – Motor Velocity GUI

GUI

74Fig. 46 – Vehicle Position GUI



75


•Background•Benjamin Roos•Timothy De Pasion•Alexander Schmidt•Kevin Block

•Rotary Encoder Resolution•Controller Software•Interrupt Timing

•Conclusion

76

Rotary Encoder Resolution

77

•Original Resolution: Approximately 20 pulses/ms

•Possible Methods on MCU:

•Multiple Timer/Counters

•External Interrupts


78

•Original Resolution: Approximately 20 pulses/ms

•Possible Methods on MCU:

•Multiple Timer/Counters

•External Interrupts


79

•Exclusive OR Gate

•Approximately 40 pulses/ms

•Cost: < $1

•Hardware Quadrature Encoding

•Approximately 80 pulses/ms

•Cost: > $10




•Conclusion

80

Controller Software

81

•Model Based PID Controller

𝑦 𝑛 = 500 ∗ 1.01 ∗ 𝑥 𝑛 − 0.9902 ∗ 𝑥 𝑛 − 1 + 𝑦(𝑛 − 1)

•Feed-Forward Controller

𝑦 𝑛 = 2170 ∗ 𝑥 𝑛 − 2167 ∗ 𝑥 𝑛 − 1 − 0.667 ∗ 𝑦(𝑛 − 1)

•Anti-Windup Code

Controller Software

82

0 2 4 6 8 10 12 14 16 18 200

2

4

6

8

10

12

14

16

Time [s]

Inp

ut

(Red

) an

d O

utp

ut

(Gre

en

) [P

uls

es/m

s]

Motor Velocity with Disturbance = 0.137 [V]

Fig. 47 – Experimental Platform Controller Test




•Conclusion

83

Experimental Platform

84

Fig. 48 – Experimental Platform Block Diagram

Interrupt Timing

85

Interrupt Designed For:

Controller: 800 μs 200 μs

Interrupt Period: 1 ms

Fig. 49 – Designed Interrupt Diagram

Interrupt Timing

86

Interrupt with no I2C communication:



Fig. 50 – Interrupt Diagram w/ I2C in Main Loop

Interrupt Timing

87

Interrupt with two I2C commands:



Fig. 51 – Interrupt Diagram w/ I2C in Interrupt

Interrupt Timing

88

Interrupt with one I2C command:

I2C Hardware Execution Time: 300 μsI2C Software Execution Time: 20 μs



Fig. 52 – Interrupt Diagram w/ I2C Alternating

Interrupt Timing

89

I2C Commands Figure:

Fig. 53 – Oscilloscope Image Grab of I2C Clock Line



90

Conclusion

•Benjamin has completed:•Anti Windup Controller•Rate Limiting•Controller Development•Simulink and Experimental Platform Torque Matching in progress

91

Conclusion

•Timothy has completed:•Simulink Integration•Feed Forward Controller•Terrain Creation•GUI Creation

92

Conclusion

•Alexander has completed:•Motor Thermals•H-Bridge Heatsink•GUI Creation

93

Conclusion

•Kevin has completed:•Controller Code

•Model Based PID Controller•Feed Forward Controller•Anti Windup Code for Feedback Controller

•Doubled Resolution•Interrupt Timing

94

Objectives

•Simulink System Integration Complete ✓

•Controller Development Complete ✓

•Controller Code Written ✓

•Experimental Platform Integration Complete ✓

•Simulink GUI Complete ✓

•System Integration in Progress ✓

•System Testing in Progress ✓

95

Summary

•On schedule for project completion

•Final Step is Integration and Testing

96

Design of a Simulink-Based Control

Workstation for Mobile Wheeled Vehicles with

Variable-Velocity Differential Motor Drives

Kevin Block, Timothy De Pasion, Benjamin Roos, Alexander SchmidtGary Dempsey

Bradley University Electrical and Computer Engineering Department

March 1, 2016

Appendix Slides

•Benjamin Roos•Timothy De Pasion•Alex Schmidt

98

Vehicle Plant

99

𝐺𝑃𝐻 𝑠 =0.0001606

1.389 ∙ 10−6𝑠2 + 0.001315𝑠 + 0.001877

𝑤𝑖𝑡ℎ 𝑝𝑜𝑙𝑒𝑠 𝑎𝑡 𝑠 = −1.43, −945.4 𝑟𝑎𝑑/𝑠

Eq. 101-1 – Vehicle Plant and Encoder Gain Model in the Laplace Domain

Continuous Feedback Controller

𝐺𝑐 𝑠 = 19.5𝑘

𝑠19.5

+ 1

𝑠

𝑤ℎ𝑒𝑟𝑒 𝑘 = 500

100

Eq. 102-1 – Continuous Feedback Controller in the Laplace Domain

Discrete Feedback Controller

101

𝐺𝑐 𝑧 = 𝑘1.01𝑧 − 0.9902

𝑧 − 1

𝑤ℎ𝑒𝑟𝑒 𝑘 = 500

Eq. 103-1 – Discrete Feedback Controller Converted with the Tustin Method and Pre-warped at 63.8 rad/s


102Fig. 54 – Step Response Curves


103Fig. 55 – Parabola Response Curve with a Parabola Input = 400 RPM/s^2

Appendix Slides


104

Rotary Encoder Model: Conversion

105

Fig. 56 – Conversion Block for Rotary Encoder

Rotary Encoder Model: 1 ms reset

106

Fig. 57 – 1 ms reset in Rotary Encoder

Rotary Encoder Model: Counter

107

Fig. 58 – Counter in Rotary Encoder

Rotary Encoder Model: Pulse Creation

108

Fig. 59 – Pulse Creation in Rotary Encoder

Rotary Encoder Model: Rounding

109

Fig. 60 – Rounding Block in Rotary Encoder

Appendix Slides


110

GUI Display

•X-Y Vehicle Position Plot•Motor Velocity Plot•Current Plot•Motor Acceleration Plot•Vehicle Velocity Plot•Vehicle Acceleration Plot•Command Plot•Error Signal Plot•Feedback Signal Plot•PWM Output Plot•Feed-Forward Command Plot

111

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