1. Motion Control: Generating Intelligent Commands for Mechatronic Devices Kelvin Peng January 31 st 2013

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

3. How to Control? Pros: Eliminates errors Disturbance rejection Cons: Stability? Sensors Controls 101: Add a Feedback Loop!

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

5. Bridge Crane Vibration Problem

6. (and solution)

7. Why is Vibration Cancelled? t1t1 t2t2

8. Solving for the two impulses Vibration Amplitude (after n impulses) Normalization Positive Impulses Time Optimality t1t1 t2t2 We want this to be zero, i.e. V=0

9. Solving for the two Impulses 3 equations, 3 unknowns Zero-Vibration (ZV) input shaper

10. Input Shaping Arbitrary Commands Slight increase in rise time ΣA i = 1 so that shaped and initial commands have same steady state

11. Bridge Crane Vibration Problem

12. Typical Responses

13. Implementing a Digital Input Shaper Unshaped Command Shaped Command

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

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

16. 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

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

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

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

20. Multi-Mode Specified Insensitivity (SI) Shaper

21. Shaping for Double-Pendulum Payloads

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

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

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

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

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

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

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

29. RF Hand-Motion Crane Control

30. Human Operator Studies

31. Human Operator Learning

32. UnshapedShaped

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

34. Tower Crane: System Overview Screen Interface

35. ME6404 Class Contest

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

37. Multi-Hoist Cranes

38. Multi-Axis Input Shaping

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

40. Experimental Results Stage Tracking Error Part Surface

41. Coordinate Measuring Machines

42. Coordinate Measuring Machine (CMM) Deflection

43. Disk Drive Head Tester

44. Painting Robot

45. GRYPHON Mine Detecting Robot

47. 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  Is excellent for applications with problematic vibrations  Is easy to implement Conclusions

48. Thank you

49. Before we go on… A General Control System