Control system health test system and method

• US 20050134284A1
• Filed: 12/22/2003
• Published: 06/23/2005
• Est. Priority Date: 12/22/2003
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated, Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Caterpillar Incorporated
• Inventors: Akasam, Sivaprasad, Baker, Thomas M., Johnson, Kris W., Hoff, Brian D.
• Granted Patent: US 7,092,848 B2
• Time in Patent Office: Days
• US Class Current: 324/511
• CPC Class Codes: E02F 9/267 Diagnosing or detecting failure of vehicles
• CPC Class Codes: G05B 23/0256 injecting test signals and analyzing monitored process response, e.g. injecting the test signal while interrupting the normal operation of the monitored system; superimposing the test signal onto a control signal during normal operation of the monitored system

Abstract

A method is provided for testing multiple elements of a work machine, including a control system, a component, a sub-component that is influenced by operations of the component, and a sensor that monitors a characteristic of the sub-component. In one embodiment, the method is performed by the control system and includes sending a command to the component to adjust a first parameter associated with an operation of the component. Also, the method includes detecting a sensor signal from the sensor reflecting a second parameter associated with a characteristic of the sub-component and determining whether the second parameter is acceptable based on the command. The control system may diagnose at least one of the elements of the work machine when the second parameter of the sub-component is not acceptable.

Claims

1. A method for testing multiple elements of a work machine, including a control system, a component, a sub-component that is influenced by operations of the component, and a sensor that monitors a characteristic of the sub-component, the method performed by the control system comprising:

sending a command to the component to adjust a first parameter associated with an operation of the component;

detecting a sensor signal from the sensor reflecting a second parameter associated with a characteristic of the sub-component;

determining whether the second parameter is acceptable based on the command; and

diagnosing at least one of the elements of the work machine when the second parameter of the sub-component is not acceptable.

2. The method of claim 1, wherein the component adjusts the first parameter based on the received command and the sub-component operates in a manner that changes the second parameter from a first value to a second value based on the adjustment of the first parameter.

3. The method of claim 1, wherein the command includes a first component and a second component superimposed on the first component.

4. The method of claim 3, wherein the second component is a time-varying component.

5. The method of claim 4, wherein the second component has a frequency of between about 0.01 Hz and about 1.0 Hz.

6. The method of claim 3, wherein the second component has a magnitude less than about 15% of a magnitude of the first component.

7. The method of claim 4, wherein determining includes:

determining whether the second parameter is responsive to the time-varying component.

8. The method of claim 2, wherein determining further includes:

determining whether the second value of the second parameter matches an expected value based on the command sent to the component.

9. The method of claim 2, wherein determining includes:

determining whether the second value of the second parameter is within a predetermined range of an expected value based on the command sent to the first component.

10. The method of claim 9, further including:

determining that the second parameter is unacceptable when the second value is not within the predetermined range of an expected value.

11. The method of claim 9, wherein diagnosing at least one of the elements of the work machine includes at least one of:

performing a communication test between the control system and another element of the work machine;

collecting first status information associated with the component;

collecting second status information associated with the sensor; and

collecting third status information from the sub-component.

12. The method of claim 11, wherein diagnosing at least one of the elements of the work machine further includes:

identifying which of the elements may be associated with the second parameter being unacceptable based on the diagnosing.

13. The method of claim 1, further including:

generating a fault message based on the diagnosis of the at least one of the elements of the work machine.

14. The method of claim 13, further including:

sending the fault message to an element included in the work machine.

15. The method of claim 13, further including:

sending the fault message to an element external to the work machine.

16. The method of claim 13, wherein the fault message includes an identification of an element determined to be a possible cause of the second parameter being unacceptable.

17. The method of claim 11, wherein the first status information includes the first parameter.

18. The method of claim 11, wherein the first status information includes a parameter that is different from the first parameter.

19. The method of claim 11, wherein collecting third status information includes:

collecting a third parameter associated with a second characteristic of the sub-component.

20. The method of claim 1, wherein the component includes a motor that provides power to the sub-component.

21. The method of claim 1, wherein the sub-component is a pump system that receives power from the component.

22. The method of claim 1, wherein diagnosing at least one of the elements of the work machine includes:

performing a software test on one or more programs executed by at least one of the control system and the component.

23. The method of claim 1, wherein diagnosing at least one of the elements of the work machine includes:

diagnosing an element different from the component, sub-component, sensor, and control system; and

determining whether the different element is affiliated with the second parameter of the sub-component being unacceptable.

24. The method of claim 1, wherein sending a command includes:

periodically sending the command to the component.

25. A system for diagnosing one or more elements of a work machine during operation of the work machine, comprising:

a control system within the work machine configured to provide a command on a data link and evaluate an operation of at least one element in the work machine based on the command;

a component configured to perform a first operation for the work machine, receive the command, and adjust a first parameter associated with the first operation based on the command; and

a sub-component configured to perform a second operation for the work machine and adjust a second parameter associated with the second operation based on the first operation of the component,

wherein the control system receives a signal having a data value associated with the second parameter and uses the data value to determine whether the second operation is being performed at an acceptable level.

26. The system of claim 25, wherein the control system is configured to periodically send the command.

27. The system of claim 25, wherein the command includes a first component and a second component superimposed on the first component.

28. The method of claim 27, wherein the second component is a time-varying component

29. The method of claim 28, wherein the second component has a frequency of between about 0.01 Hz and about 1.0 Hz.

30. The method of claim 27, wherein the second component has a magnitude less than about 15% of a magnitude of the first component.

31. The system of claim 25, wherein the control system is further configured to:

compare the data value to an expected data value for the second parameter when the first parameter is adjusted according to the command.

32. The system of claim 25, wherein the control system is further configured to:

compare the data value to an expected range of data values for the second parameter when the first parameter is adjusted according to the command.

33. The system of claim 25, wherein the sub-component includes a sensor that provides the signal to the control system.

34. The system of claim 25, wherein the control system is further configured to:

evaluate the operation of at least one of the component, sub-component, and control system when the second operation is not acceptable.

35. The system of claim 25, wherein the control system is connected to the component by a data link and, when the second operation is not acceptable, the control system tests the data link by transmitting a test message to the component over the data link.

36. The system of claim 25, wherein when the second operation is not acceptable, the control system collects another signal reflecting a third parameter associated with an operation of an element different than the sub-component.

37. The system of claim 36, wherein the different element is one of the component and a mechanism associated with the component.

38. The system of claim 25, wherein when the second operation is not acceptable, the control system tests program code executed by at least one of the control system and the component.

39. The system of claim 25, wherein when the second operation is unacceptable, the control system performs a diagnosis process to identify a potential source of the unacceptable second operation of the sub-component and generates a fault message including the identity of the potential source.

40. The system of claim 25, wherein the first parameter is a speed of a motor included in the component.

41. The system of claim 40, wherein the second parameter is pressure produced by the sub-component based on the speed of the motor.

42. The system of claim 40, wherein the second parameter is temperature affected by the second operation of the sub-component.

43. The system of claim 40, wherein the second parameter is a level of a gas produced by the second operation of the sub-component.

44. The system of claim 25, wherein the control system determines whether the second operation is being performed at an acceptable level by:

comparing the second parameter data value with an expected second parameter value based on the first parameter adjusted by the command; and

determining whether the second parameter value is within a predetermined range of the expected second parameter value.

45. The system of claim 25, wherein the control system evaluates the operation of the at least one element in the work machine without user intervention.

46. The system of claim 25, wherein the component is configured to evaluate the operation of at least one of itself and another element in the work machine without intervention of the control system.

47. A computer-readable medium including instructions for performing a method, when executed by a processing unit, for diagnosing one or more elements of a work machine, the method comprising:

sending a command to the component to adjust a first parameter associated with an operation of the component;

detecting a sensor signal from the sensor reflecting a second parameter associated with a characteristic of the sub-component;

determining whether the second parameter is acceptable based on the command; and

diagnosing at least one of the elements of the work machine when the second parameter of the sub-component is not acceptable.

48. The computer-readable medium of claim 47, wherein the command includes a first component and a time-varying second component superimposed on the first component.

49. The computer-readable medium of claim 47, further including determining whether the second parameter is responsive to the time-varying second component.

50. An apparatus for diagnosing one or more elements of a work machine, comprising:

a processing unit; and

a memory including;

program code for performing a diagnosis process including the steps of;

periodically sending commands to a component that adjusts the operation of the component, wherein at least one of the commands includes a first component and a time-varying second component superimposed on the first component,

receiving a sensor signal from a sensor monitoring a characteristic of a sub-component that operates in a manner based on the operation of the component,

determining whether the characteristic of the sub-component is acceptable in relation to the operation of the component adjusted by the command,

determining whether the characteristic is responsive to the time-varying second component,

diagnosing the one or more elements of the work machine when the characteristic of the sub-component is unacceptable, and

determining whether any one of the one or more elements is a cause of the characteristic being unacceptable,

wherein the one or more elements includes at least the component and sub-component.