Method of and apparatus for evaluating the performance of a control system

• US 20050256661A1
• Filed: 05/13/2004
• Published: 11/17/2005
• Est. Priority Date: 05/13/2004
• Status: Active Grant

• Current Assignee: Tyco Fire & Security GmbH (Johnson Controls International plc)
• Original Assignee: Johnson Controls Technology Company (Johnson Controls International plc)
• Inventors: Singhal, Ashish, Salsbury, Timothy I.
• Granted Patent: US 7,024,336 B2
• Time in Patent Office: Days
• US Class Current: 702/113
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/49 ensuring correct operation, e.g. by trial operation or configuration checks

Abstract

A method for and apparatus for evaluating the performance of a control system are disclosed. The method includes receiving data from the control system, wherein the data is received by a passive testing function, and calculating a parameter related to the performance of the control system using the passive testing function. The apparatus includes a processor operable to execute a passive testing function, wherein the passive testing function is configured to receive data from the control system and calculate a parameter related to the performance of the control system. The apparatus may also include an active testing function, wherein the active testing function is configured to provide a sequence of step changes to an input of the control system, receive data from the control system in response to the sequence of step changes, and calculate a parameter related to the performance of the control system.

Claims

1. (canceled)

3. A method of evaluating the performance of a control system, the method comprising:

receiving data from the control system, wherein the data is received by a passive testing function; and

calculating a parameter related to the performance of the control system using the passive testing function;

wherein the passive testing function is a load disturbance detection test, and wherein calculating the parameter related to the performance of the control system includes determining an autocorrelation value from data received from the control system.

4. The method of claim 3, wherein calculating the parameter related to the performance of the control system further includes determining a confidence interval from data received from the control system.

5. The method of claim 4, wherein calculating the parameter related to the performance of the control system further includes determining a normalized index value when data received from the control system exceeds the confidence interval.

6. The method of claim 5, wherein calculating the parameter related to the performance of the control system further includes determining a first-order-plus-time-delay model for a device in the control system.

8. A method of evaluating the performance of a control system, the method comprising:

receiving data from the control system, wherein the data is received by a passive testing function; and

calculating a parameter related to the performance of the control system using the passive testing function;

wherein the passive testing function is an oscillation detection test, and wherein calculating the parameter related to the performance of the control system includes determining repeating patterns from data received from the control system; and

wherein data received from the control system includes an error signal, and wherein determining the repeating patterns from data received from the control system includes determining a similarity index value related to alternating area values associated with the error signal.

9. The method of claim 8, wherein the control system includes a feedback control loop comprising a controller and a plant.

10. A method of evaluating the performance of a control system, the method comprising:

receiving data from the control system, wherein the data is received by a passive testing function; and

calculating a parameter related to the performance of the control system using the passive testing function;

wherein the control system includes a feedback control loop comprising a controller and a plant; and

wherein the controller is a proportional plus integral (PI) controller.

2. The method of claim 10, wherein the passive testing function is at least one of a load disturbance detection test and an oscillation detection test.

7. The method of claim 2, wherein the passive testing function is an oscillation detection test, and wherein calculating the parameter related to the performance of the control system includes determining repeating patterns from data received from the control system.

11. The method of claim 10, wherein the control system is a heating, ventilating, and air conditioning system.

12. The method of claim 10, further comprising displaying the parameter related to the performance of the control system to a user.

13. The method of claim 10, wherein data received from the control system includes discrete data samples of an error signal associated with the control system.

14. The method of claim 10, wherein the passive testing function is a non-invasive testing function.

15. (canceled)

16. The apparatus of claim 424, wherein the passive testing function is at least one of a load disturbance detection test and an oscillation detection test.

21. The apparatus of claim 16, wherein the passive testing function is an oscillation detection test, and wherein calculating the parameter related to the performance of the control system includes determining repeating patterns from data received from the control system.

17. An apparatus for evaluating the performance of a control system, the apparatus comprising:

a processor operable to execute a passive testing function, wherein the passive testing function is configured to;

receive data from the control system; and

calculate a parameter related to the performance of the control system;

wherein the passive testing function is a load disturbance detection test, and wherein calculating the parameter related to the performance of the control system includes determining an autocorrelation value from data received from the control system.

18. The apparatus of claim 17, wherein calculating the parameter related to the performance of the control system further includes determining a confidence interval from data received from the control system.

19. The apparatus of claim 18, wherein calculating the parameter related to the performance of the control system further includes determining a normalized index value when data received from the control system exceeds the confidence interval.

20. The apparatus of claim 19, wherein calculating the parameter related to the performance of the control system further includes determining a first-order-plus-time-delay model for a device in the control system.

22. An apparatus for evaluating the performance of a control system, the apparatus comprising:

a processor operable to execute a passive testing function, wherein the passive testing function is configured to;

receive data from the control system; and

calculate a parameter related to the performance of the control system;

wherein the passive testing function is an oscillation detection test, and wherein calculating the parameter related to the performance of the control system includes determining repeating patterns from data received from the control system; and

wherein data received from the control system includes an error signal, and wherein determining the repeating patterns from data received from the control system includes determining a similarity index value related to alternating area values associated with the error signal.

23. The apparatus of claim 22, wherein the control system includes a feedback control loop comprising a controller and a plant.

24. An apparatus for evaluating the performance of a control system, the apparatus comprising:

a processor operable to execute a passive testing function, wherein the passive testing function is configured to;

receive data from the control system; and

calculate a parameter related to the performance of the control system;

wherein the control system includes a feedback control loop comprising a controller and a plant; and

wherein the controller is a proportional plus integral (PI) controller.

25. The apparatus of claim 24, wherein the control system is a heating, ventilating, and air conditioning system.

26. The apparatus of claim 24, further comprising a display configured to display the parameter related to the performance of the control system to a user.

27. The apparatus of claim 24, wherein data received from the control system includes discrete data samples of an error signal associated with the control system.

28. The apparatus of claim 24, wherein the processor is further operable to execute an active testing function.

29. The apparatus of claim 28, wherein the active testing function is configured to identify static nonlinearity in the control system.

32. The apparatus of claim 28, wherein the active testing function is configured to identify dynamic nonlinearity in the control system.

33. The apparatus of claim 28, wherein the active testing function is configured to determine an overall performance index for the control system.

35. The apparatus of claim 24, wherein the passive testing function is a non-invasive testing function.

30. An apparatus for evaluating the performance of a control system, the apparatus comprising:

a processor operable to execute a passive testing function, wherein the passive testing function is configured to;

receive data from the control system; and

calculate a parameter related to the performance of the control system;

wherein the processor is further operable to execute an active testing function;

wherein the active testing function is configured to identify static nonlinearity in the control system; and

wherein the active testing function is further configured to determine a mathematical function to remove the static nonlinearity from the control system.

31. An apparatus for evaluating the performance of a control system, the apparatus comprising:

a processor operable to execute a passive testing function, wherein the passive testing function is configured to;

receive data from the control system; and

calculate a parameter related to the performance of the control system;

wherein the processor is further operable to execute an active testing function; and

wherein the active testing function is configured to identify hysteresis in the control system.

34. An apparatus for evaluating the performance of a control system, the apparatus comprising:

a processor operable to execute a passive testing function, wherein the passive testing function is configured to;

receive data from the control system; and

calculate a parameter related to the performance of the control system;

wherein the processor is further operable to execute an active testing function; and

wherein the active testing function is configured to determine a first-order-plus-time-delay model for a device in the control system.

36. (canceled)

38. An apparatus for evaluating the performance of a control system, the apparatus comprising:

means for executing a passive testing function, wherein the passive testing function is configured to;

receive data from the control system; and

calculate a parameter related to the performance of the control system;

wherein the passive testing function is a load disturbance detection test, and wherein calculating the parameter related to the performance of the control system includes determining an autocorrelation value from data received from the control system.

39. The apparatus of claim 38, wherein calculating the parameter related to the performance of the control system further includes determining a confidence interval from data received from the control system.

40. The apparatus of claim 39, wherein calculating the parameter related to the performance of the control system further includes determining a normalized index value when data received from the control system exceeds the confidence interval.

41. The apparatus of claim 40, wherein calculating the parameter related to the performance of the control system further includes determining a first-order-plus-time-delay model for the control system.

43. An apparatus for evaluating the performance of a control system, the apparatus comprising:

means for executing a passive testing function, wherein the passive testing function is configured to;

receive data from the control system; and

calculate a parameter related to the performance of the control system;

wherein the passive testing function is an oscillation detection test, and wherein calculating the parameter related to the performance of the control system includes determining repeating patterns from data received from the control system; and

wherein data received from the control system includes an error signal, and wherein determining the repeating patterns from data received from the control system includes determining a similarity index value related to alternating area values associated with the error signal.

44. The apparatus of claim 43, wherein the control system includes a feedback control loop comprising a controller and a plant.

45. An apparatus for evaluating the performance of a control system, the apparatus comprising:

means for executing a passive testing function, wherein the passive testing function is configured to;

receive data from the control system; and

calculate a parameter related to the performance of the control system;

wherein the control system includes a feedback control loop comprising a controller and a plant; and

wherein the controller is a proportional plus integral (PI) controller.

37. The apparatus of claim 45, wherein the passive testing function is at least one of a load disturbance detection test and an oscillation detection test.

42. The apparatus of claim 37, wherein the passive testing function is an oscillation detection test, and wherein calculating the parameter related to the performance of the control system includes determining repeating patterns from data received from the control system.

46. The apparatus of claim 45, wherein the control system is a heating, ventilating, and air conditioning system.

47. The apparatus of claim 45, further comprising means for displaying the parameter related to the performance of the control system to a user.

48. The apparatus of claim 45, wherein data received from the control system includes discrete data samples of an error signal associated with the control system.

49. (canceled)

50. (canceled)

51. (canceled)