1. Active Suspension System Test Platform – Controls Advisor: Mr. Steven Gutschlag Presented: 29 April 2004 Project Member: Jerry L. Campbell Senior Presentation

2. Outline I. Project Overview II. Functional Description III. System Block Diagram IV. System Identification V. Plant Model VI. System Performance VII. Problems Encountered VIII. Future Work IX. Questions

3. Reliable Test Platform Digital Controller for DC Actuator Used by Future Bradley University Projects Overview

4. System InputsOutputs Desired Platform Motion (R)Actual Platform Motion (C) Note: Desired system response is C=R, or C/R = 1.0 EMAC Micropac 535 micro-controller based development board (Controller) InputsOutputs Keypad (Desired Platform Motion)Actuator Drive Signal Max. Platform Motion AmplitudeLCD Display Actuator (plant) InputsOutputs Error Signal from Controller Platform Movement Position Signal Disturbance Force (Load)

5. Modes of Operation Sinusoidal Step Triangular Note: Step and Triangle functions can be single or continuous

6. Software Initialization Flow Chart

7. Basic System Block Diagram Shown in a General Configuration Input Voltage Signal Representing the Desired Platform Motion ( Provided by the Micro-Controller ) Actuator Plant EMAC MicroPac 535 Development System Digital Controller Input Platform Motion

8. Detailed Spec Sheet Not Available Need Accurate Mathematical Model Obtained Via Frequency Response and Load vs. Speed Measurements System Identification Identification

9. Block Diagram of a Simple DC Machine ( Open Loop)

10. Sample Frequency Response Data Sample

11. 10 0 1 2 11 12 13 14 15 16 17 Frequency Response Actuator Velocity [dB] Applied Frequency [w] Red => Slope from pencil Line Blue=> Slope from Cursors

12. 10 0 1 2 3 0 2 4 6 8 12 14 16 18 20 Frequency Response Actuator Velocity [dB] Applied Frequency [w] Red => Slope from pencil Line Blue=> Slope from Cursors -3dB point at ~ 42 rad/sec

13. 10 0 1 2 -100 -90 -80 -70 -60 -50 -40 -30 -20 -10 0 Applied Frequency (rad/sec) Phase (degrees) Phase (peak to inflection) VS. Frequency ~28

14. Preliminary Simulink Model for the Warner Linear Actuator Including Non-Linear Effects

15. Backlash Effects Input Position

16. Simplified Model Assumptions System is Linear Backlash Not Present Dead Band Not Present

17. Position Va Force (load) System Model Simplified System Model

18. Simplified System Simulink Model

19. PM Determination

20. Phase Margin Determination

21. Position Without Controller Position With Controller System Performance Lower Actuator Position Limit

22. Simplified System Simulink Model

23. Input K = 10 K = 80 K = 40 K = 20 System Performance Note: Backlash Effects Minimized as Gain Increases

24. System Step Response Input Position K = 40

25. Other Controller Options and Obstacles Integrator PI Controller

26. Problems Encountered Current Limiting Caused Inadequate Data Time Required for System Identification Insufficient Time Left to Implement Digital Control

27. Future Work Select Practical Hardware Micro-Controller Code Implement Digital Controller W/ EMAC Construct Test Platform

28. Questions

29. Questions

30. Questions

31. Lumped Parameter Model