1. Auto-tuning of PID controllers
Mini course at Danfoss A/S
Henrik Rasmussen
Department of Control Engineering
Aalborg University
11/13/2018
Auto-tuning of PID controllers

2. Auto-tuning of PID controllers
Content
The Satt Control auto-tuner in a distributed control system
The Self-tuning Regulator concept
PID-algorithm – textbook and modifications
Ziegler-Nichols frequency response method
Relay tuning in closed loop
Bump-less transfer and anti integrator windup
Gain scheduling
Choice of controller type
11/13/2018
Auto-tuning of PID controllers

3. Auto-tuning of PID controllers
References
Automatic tuning of PID controllers, Åstrøm & Hägglund
Adaptive Control, Åstrøm & Wittenmark
Automatic tuning of PID-regulators, H. Rasmussen URL,
11/13/2018
Auto-tuning of PID controllers

4. Auto-tuning of PID controllers
11/13/2018
Auto-tuning of PID controllers

5. Distributed control system
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Auto-tuning of PID controllers

6. SattControl Auto-tuner
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Auto-tuning of PID controllers

7. Auto-tuning of PID controllers
Self Tuning Regulator
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Auto-tuning of PID controllers

8. Textbook and modified PID-algorithm
The ''textbook'' version of the PID controller can be described by the
equation
Modification of ''textbook'' version
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Auto-tuning of PID controllers

9. Controller Parameters
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Auto-tuning of PID controllers

10. Ziegler-Nichols ultimate period method
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Auto-tuning of PID controllers

11. Auto Tuning based on relay feedback
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Auto-tuning of PID controllers

12. Auto-tuning of PID controllers
Nyquist plot
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Auto-tuning of PID controllers

13. Phase and amplitude margin
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Auto-tuning of PID controllers

14. Auto-tuning of PID controllers
1. Break
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Auto-tuning of PID controllers

15. Auto-tuning of PID controllers
Relay with hysteresis
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Auto-tuning of PID controllers

16. Auto-tuning of PID controllers
Stable limit cycle
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Auto-tuning of PID controllers

17. Auto-tuning of PID controllers
Offset
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Auto-tuning of PID controllers

18. Auto tuning of PID regulators
Ziegler-Nichols tuning Spec. phase and amplitude margin
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Auto-tuning of PID controllers

19. Auto-tuning of PID controllers
Actuator Saturation
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Auto-tuning of PID controllers

20. Auto-tuning of PID controllers
Integrator windup
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Auto-tuning of PID controllers

21. Regulator modified to avoid windup
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Auto-tuning of PID controllers

22. Regulator modified to avoid windup
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Auto-tuning of PID controllers

23. Anti windup for PID controller
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Auto-tuning of PID controllers

24. Discrete time PI controller
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Auto-tuning of PID controllers

25. Auto-tuning of PID controllers
p and q operators
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Auto-tuning of PID controllers

26. Discrete Time PID-controller
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Auto-tuning of PID controllers

27. Integrator windup and bumpless transfer
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Auto-tuning of PID controllers

28. Auto-tuning of PID controllers
2. Break
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Auto-tuning of PID controllers

29. Open loop step response
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Auto-tuning of PID controllers

30. Closed loop with PI control ?!?
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Auto-tuning of PID controllers

31. Anti integrator windup
Measured actuator output Estimated actuator output
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Auto-tuning of PID controllers

32. Observer: A=1-exp(-Ts/(0.1*Ti))
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Auto-tuning of PID controllers

33. Observer: A=1-exp(-Ts/Ti))
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Auto-tuning of PID controllers

34. PI controller and a nonlinear valve
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Auto-tuning of PID controllers

35. Step response for different levels
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Auto-tuning of PID controllers

36. PI controller with gain scheduling
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Auto-tuning of PID controllers

37. Step response for different levels
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Auto-tuning of PID controllers

38. Gain scheduling principle
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Auto-tuning of PID controllers

39. Bumpless transfer between controllersy u y
ref 1 A1 T1 G
A1-R1
-S1 1 A2 T2
A2-R2
-S2
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Auto-tuning of PID controllers

40. Auto-tuning of PID controllers
Choice of Controller
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Auto-tuning of PID controllers

41. Auto-tuning of PID controllers
Conclusions
The Self-tuning Regulator concept
Relay experiment gives ultimate period and gain
Ziegler-Nichols tuning
Tuning based on phase and amplitude margin
Bump-less transfer and anti integrator windup
PID-algorithm – textbook and modifications
Gain scheduling
Choice of controller type
11/13/2018
Auto-tuning of PID controllers