Dual signal correlation system

• US 20050031056A1
• Filed: 08/08/2003
• Published: 02/10/2005
• Est. Priority Date: 08/08/2003
• Status: Abandoned Application

• Current Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Thomas, Richard J.
• Application Number:
  US10/637,398
• Publication Number:
  US 20050031056A1
• Time in Patent Office: Days
• US Class Current: 375/343
• CPC Class Codes: B60T 2270/413 Plausibility monitoring, cross check, redundancy
• CPC Class Codes: B60T 8/885 using electrical circuitry

Abstract

A dual signal correlation system including a component to be monitored and a sensor system for monitoring the status of the component. The sensor system provides at least first and second data signals relating to the status of the component. The dual signal correlation system further includes a processing system for receiving, monitoring and selectively modifying the first and second data signals of the sensor system. The processing system compares a current value for the first data signal to a current value for the second data signal, and wherein if the current value for the first data signal is determined not to be correlated or is determined to be uncorrelated with the current value for the second data signal, a previously measured value for the first data signal, instead of the current value for the first data signal, is used for subsequent processing.

Claims

1. A dual signal correlation system comprising:

a sensor system for monitoring the status of a component, said sensor system providing at least first and second data signals relating to the status of said component; and

a processing system for receiving and selectively modifying said first and second data signals of said sensor system, wherein said processing system compares a current value for said first data signal to a current value for said second data signal, and wherein if said current value for said first data signal is determined not to be correlated with said current value for said second data signal or is determined to be uncorrelated with said current value for said second data signal, a previously measured value for said first data signal, instead of said current value for said first data signal, is used for subsequent processing.

2. The system of claim 1 further including a controller, and wherein said processing system provides an output of said processing system to said controller for subsequent processing to determine feedback controls to said component.

3. The system of claim 2 wherein said output includes said current value for said second data signal and, if said current value for said first data signal is determined to not be correlated or to be uncorrelated with said current value for said second data signal, said output includes said previously measured value for said first data signal, and wherein if said current value for said first data signal is determined to be correlated or not to be uncorrelated with said current value for said second data signal, said output includes said current value for said first data signal.

4. The system of claim 1 wherein said current value for said second data signal is used for subsequent processing. The system of claim 1 wherein said processing system includes a comparator for comparing said current value for said first data signal and said current value for second data signal, memory means for storing previously supplied values for said first and second data signals, and correction means for selectively substituting a previously measured value for said current value of said first data signal.

5. The system of claim 1 wherein said processing system is configured such that if said current value for said first data signal is determined to be correlated with said current value for said second data signal, the current values of both said first and second data signals are used for subsequent processing.

6. The system of claim 1 wherein said first and second data signals are physically related to each other.

7. The system of claim 1 further comprising said component, and wherein said component is a movable component.

8. The system of claim 7 wherein said component is a brake caliper operatively coupled to a brake pad, and wherein said first data signal is indicative of a force applied by said caliper to another component or of the force applied by said brake pad to a rotor and said second data signal is indicative of a position of said caliper or said brake pad.

9. The system of claim 1 wherein said sensor system includes two sensors, each of which provides one of said data signals.

10. The system of claim 1 wherein said sensor system provides updated values for said first and second data signals at spaced time intervals.

11. The system of claim 1 wherein said processing system is configured such that said previously measured value of said first data signal used for subsequent processing is the most recent value of said first data signal when said first and second signals were last determined to be correlated.

12. The system of claim 1 wherein said current value for said first data signal is determined not to be correlated or to be uncorrelated with said current value for said second data signal by performing a mathematical operation or operations upon both of said first or second data signals to provide modified values for said first and second data signals and comparing the modified values.

13. The system of claim 12 wherein said mathematical operation or operations includes a derivative of said first and second data signals.

14. The system of claim 13 wherein said derivative is a first time derivative which takes into account previous values for said first and second data signals.

15. The system of claim 12 wherein each modified value includes or incorporates a difference between the current values for said first and second data signals and a previous value for said respective first and second data signals.

16. The system of claim 12 wherein if the signs of said modified values are the same, said first and second data signals are considered to be correlated, and if the signs of said modified values are not the same, said first and second data signals are considered to be not correlated.

17. The system of claim 1 wherein said processing system determines whether said first and second data signals were correlated in a most recent, previous loop.

18. The system of claim 17 wherein said processing system determines if said first and second data signals were correlated in the most recent, previous loop, and if the first and second data signals were correlated then the processing system determines whether said first and second data signals are now uncorrelated using a first set of conditions.

19. The system of claim 18 wherein said processing system determines if said first and second data signals were uncorrelated in the most recent, previous loop, and if the first and second data signals were uncorrelated then the processing system determines whether said first and second data signals are now correlated using a second set of conditions.

20. A feedback system for monitoring and modifying first and second data signals provided to the feedback system, wherein said feedback system is configured to compare a current value for said first data signal to a current value for said second data signal, and wherein if said current value for said first data signal is determined not to be correlated with said current value for said second data signal, a previously measured value for said first data signal, instead of said current value for said first data signal, is output from said system for subsequent processing.

21. A method for providing feedback including the steps of:

receiving from a sensor system current values for first and second data signals;

determining whether said current values for said first and second data signals are correlated, and wherein if said current values for said data signals are determined not to be correlated, a previously measured value for at least one of said data signals is provided for subsequent processing.

22. The method of claim 21 further including the step of providing an output to a controller for subsequent processing to determine feedback controls to a component.

23. The method of claim 22 wherein said output includes said current value for said second data signal and, if said current value for said first data signal is determined to not be correlated with said current value for said second data signal, said output includes said previously measured value for said first data signal, and wherein if said current value for said first data signal is determined to be correlated with said current value for said second data signal, said output includes said current value for said first data signal.

24. The method of claim 23 further including the step of said controller utilizing said output to determine said feedback controls to said component.

25. The method of claim 23 wherein if said current value for said first data signal is determined to be correlated with said current value for said second data signal, the current values of both said first and second data signals are used for subsequent processing.

26. The method of claim 23 wherein said previously measured value of said first data signal used for subsequent processing is the most recent value of said first data signal when said first and second signals were last determined to be correlated.

27. The method of claim 23 wherein said current value for said first data signal is determined not to be correlated with said current value for said second signal by performing a mathematical operation or operations upon both of said first or second data signals to provide modified values for said first and second data signals and comparing the modified values.

28. The method of claim 27 wherein said mathematical operation or operations includes a derivative of said first and second data signals.

29. The method of claim 28 wherein said derivative is a first time derivative which takes into account previous values for said first and second data signals.

30. The method of claim 27 wherein each modified value includes or incorporates a difference between the current values for said first and second data signals and a previous value for said respective first and second data signals.

31. The method of claim 27 wherein if the signs of said modified values are the same, said first and second data signals are considered to be correlated, and if the signs of said modified values are not the same, said first and second data signals are not considered to be correlated.

32. The method of claim 21 wherein said first and second data signals are physically related to each other.

33. The method of claim 21 wherein said sensor system monitors the status of a component, and wherein said first and second data signals are related to the status of said component.

34. The method of claim 33 wherein said component is a brake caliper operatively coupled to said brake rotor, and wherein said first data signal is indicative of a force applied by said caliper to another component or of the force applied by said brake pad to a rotor and said second data signal is indicative of a position of said caliper or of said brake pad.

35. The method of claim 21 wherein said sensor system includes two sensors, and wherein the method includes each of said sensors providing one of said data signals

36. The method of claim 35 wherein said sensor system provides updated values for said first and second data signals at spaced time intervals.

37. The method of claim 21 further including the additional step of determining whether said first and second data signals were correlated in a most recent, previous loop.

38. The method of claim 37 wherein said additional determining step includes determining whether said first and second data signals were correlated in the most recent, previous loop, and if the first and second data signals were correlated then checking whether said first and second data signals are now uncorrelated using a first set of conditions.

39. The method of claim 38 wherein said additional determining step includes determining whether said first and second data signals were uncorrelated in the most recent, previous loop, and if the first and second data signals were uncorrelated then checking whether said first and second data signals are now correlated using a second set of conditions.