1. 4/19/2006E597 Presentation1 E597 Steering System Input Servo Modeling & Vehicle Validation by Jerome Ivan

2. 4/19/2006E597 Presentation2 Summary Project goals Vehicle Data Servo description Steering servo model Potential reasons for inaccurate emulation Things gone wrong Things that could have been done better Will I continue? Schedule shortfalls Analysis Tools

3. 4/19/2006E597 Presentation3 Project Goals Take steering response data from steering servo disconnected from vehicle Take steering response data from vehicle as a function of speed steering servo connected Develop and validate steering servo model using test data & bond graph model Use data from the vehicle to derive lump sum steering system C, I and R using the bond graph model

4. 4/19/2006E597 Presentation4 Steering Freewheeling Kd = 1000 +/- 10deg.

5. 4/19/2006E597 Presentation5 Steering Freewheeling Kd = 0 +/- 10deg.

6. 4/19/2006E597 Presentation6 Steering Freewheeling / No Steering Wheel Kd = 1000 +/- 90deg.

7. 4/19/2006E597 Presentation7 Steering Freewheeling / No Steering Wheel Kd = 0 +/- 90deg.

8. 4/19/2006E597 Presentation8 Steering Vehicle 0 MPH Kd = 1000 +/- 90deg.

9. 4/19/2006E597 Presentation9 Steering Vehicle 10 MPH Kd = 1000 +/- 90deg.

10. 4/19/2006E597 Presentation10 Servo System Description Steering Servo System

11. 4/19/2006E597 Presentation11 Servo System Description Motor & Chain Drive

12. 4/19/2006E597 Presentation12 Servo System Measurements (no motor data) Ix armature = 452mkg-m^2 (calculated) Coil R = 0.4 ohm (measured) Coil I = 70uH (measured) Steering Shaft K = 100Nm/rad (measured) Bearing R = 0.05Nms/rad (estimated) Motor produces 2.5N @ 54amps Motor K =.0463Nm/A (calculated)

13. 4/19/2006E597 Presentation13 Servo System Measurements (no motor data) Homemade Motor Curve

14. 4/19/2006E597 Presentation14 Steering Servo Model Simulink Controller

15. 4/19/2006E597 Presentation15 Steering Servo Model Bond Graph

16. 4/19/2006E597 Presentation16 20-Sim Servo Simulation Fails to emulate ringing.

17. 4/19/2006E597 Presentation17 Possible Reasons for Inaccurate Emulations 20-Sim PD Controller was an invalid representation of the Simulink controller. Inaccurate bond graph parameters Bandwidth limitations of actual controller not found in simulation. Bond graph model has infinite current source / vehicle had a 30% duty cycle limit or about a 20Amp limit.

18. 4/19/2006E597 Presentation18 Possible Reasons for Inaccurate Emulations Bandwidth of actual controller

19. 4/19/2006E597 Presentation19 Possible Reasons for Inaccurate Emulations Bandwidth of simulation controller

20. 4/19/2006E597 Presentation20 Things Gone Wrong I was never able to accurately emulate steering controller. I Could not complete the task of deriving lump-sum I, C & R for the steering system. Not enough time to run the HP Signal Analyzer in vehicle (bode plots.) No motor data

21. 4/19/2006E597 Presentation21 Things That Could Have Been Better I Could have shut off Simulink steering controller and taken open-loop data in vehicle. Used open-loop data to validate bond graph model without PD controller. I Could have attempted to build a more representative discrete controller in 20- Sim

22. 4/19/2006E597 Presentation22 Will I continue to use the Bond Graph Method? Yes, the bond graph method works well for driving the state space equations. Everyone in the department uses Simulink and is at the mercy of SAE documentation for developing models.

23. 4/19/2006E597 Presentation23 Schedule Short Falls Week 1- (Mar 27-31) run test stand & build servo bond graph Week 2- Validate servo model & take data in vehicle (could not validate servo model) Week 3- Validate lump sum vehicle model & finish PPT (without accurate servo model, there was no sense in trying to infer lump sum steering system I, C & R.

24. 4/19/2006E597 Presentation24 Analysis Tools 20-sim MathWorks Simulink MatLab HP Full Bridge Tester Norton, R. L, Machine Design An Integrated Approach, Prentice-Hall Inc.,1998

25. 4/19/2006E597 Presentation25 FIN Ford F-250 Roaming Robot NQE