1. Motion Control: Generating Intelligent Comands for Mechatronic Devices Kelvin Peng Feburary 7 th 2012

2. What is Control? Getting the System to do What you Want

3. How to Control? Add a Feedback Loop Pros: Eliminates errors Disturbance rejection Cons: Stability? Sensors

4. Let’s go back to simple control Today’s topic: How to design the command generator Pros: Simple, no sensors Stable (if plant is stable) Accurate model not needed Cons: No disturbance rejection Increase rise time

5. Before we go on… A General Control System

6. Bridge Crane Vibration Problem

7. (and solution)

8. Why is Vibration Cancelled?

9. Derivation for a Simple Case Constraints Vibration Amplitude (At the end of n impulses) Normalization Positive Impulses Time Optimality

10. Simple Derivation (V=0, 2 impulses) 3 equations, 3 unknowns

11. Input Shaping Arbitrary Commands Slight increase in rise time ΣA i = 1 so that shaped and initial commands have same steady state From previous example: Zero-Vibration (ZV) shaper

12. Bridge Crane Vibration Problem

13. Typical Responses

14. Implementing a Digital Input Shaper Unshaped Command Shaped Command

15. Shaper Robustness Insensitivity – the width of a sensitivity curve where vibration remains under V tol, the tolerable level of vibration

16. Increasing Shaper Robustness Insensitivity – the width of a sensitivity curve where vibration remains under V tol, the tolerable level of vibration

17. Increasing Shaper Robustness Extra Insensitive (EI) Shaper Insensitivity – the width of a sensitivity curve where vibration remains under V tol, the tolerable level of vibration

18. Increasing Shaper Robustness Like a Boss Tradeoff: More impulses are needed, and therefore slower rise time.

19. Multi-Mode Input Shaping Design a shaper for each mode, then convolve to get a shaper that eliminates both modes

20. ZV Shaper for 1 Hz ZV Shaper for 2 Hz X ZV Shaper for 1 Hz and 2 Hz

21. Multi-Mode Specified Insensitivity (SI) Shaper

22. Shaping for Double-Pendulum Payloads

23. Shapers with Negative Impulses Unity Magnitude UMZV shaper Negative shapers: Faster But less robust May excite un- modeled higher modes

24. Special Case: Negative Shapers for On-Off Actuators Not On/Off UMZV Shaper: On-Off

25. On-Off Thrusters: Flexible Satellites (Tokyo Institute of Technology)

26. On-Off Thrusters: Flexible Satellites (Tokyo Institute of Technology)

27. Input Shaping With Feedback Control Input Shaper * Cascaded set of 2 nd order systems Collapse the feedback loop

28. Input Shaping and Feedback Control: Experimental Data Disturbance at EndDisturbance During Motion

29. Input Shaping Inside the Feedback Loop: Hand-Motion Crane Control

30. RF Hand-Motion Crane Control

31. Human Operator Studies

32. Human Operator Learning

33. UnshapedShaped

34. Portable Tower Crane 2mx2mx340 o Interfaces: Pendent, GUI, Internet GUI Overhead Camera Used by Researchers and Students in Atlanta, Japan, Korea

35. Tower Crane: System Overview Screen Interface

36. ME6404 Class Contest

37. Other Applications Many types of cranes Milling machines Coordinate measuring machines Disk drives Long reach robots Spacecraft

38. Scale of Micro Meters (10 -6 m) High Spindle Speeds (120 kRPM) Application of Command Shaping to Micro Mills

39. Experimental Results Stage Tracking Error Part Surface

40. Coordinate Measuring Machines

41. Coordinate Measuring Machine (CMM) Deflection

42. Disk Drive Head Tester

43. Painting Robot

44. GRYPHON Mine Detecting Robot

46. Every control method has strengths and weaknesses (Feedback is not a magic cure-all) The command issued to a system has a significant influence on its response Input shaping  Can dramatically reduce system vibration  Is easy to implement Conclusions

47. Thank you