Time stress measurement device

• US 5,600,576 A
• Filed: 03/11/1994
• Issued: 02/04/1997
• Est. Priority Date: 03/11/1994
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Broadwater, Stuart P., Skeberdis, Paul W., Cockey, Edward A., Gibson, White E.
• Primary Examiner(s): Voeltz, Emanuel T.
• Assistant Examiner(s): Smith, Demetra R.
• Application Number:
  US08/209,056
• Time in Patent Office: 1,061 Days
• Field of Search: 364/200, 364/420, 364/571.03, 364/551.01, 364/550
• US Class Current: 702/187
• CPC Class Codes: G01D 9/005 Solid-state data loggers
• CPC Class Codes: G05B 23/0229 knowledge based, e.g. expert systems; genetic algorithms
• CPC Class Codes: G06F 11/2205 using arrangements specific to the hardware being tested
• CPC Class Codes: G06F 2201/835 Timestamp

Abstract

A time stress measurement device is provided for use in diverse electronic and electromechanical system. The TSMD collects environmental data applied to a system, collects event data experienced by the system, time-stamps the environmental and event data, compares the environmental data to various preset thresholds, and stores the time-stamped environmental data and time-stamped event data. The data is stored in various data structures, including recent environmental data, historical environmental data, peak environmental data, and event signature data. The environmental data and event data can be retrieved by maintenance personnel to isolate and analyze system faults and failures. The device can further be capable of sending a test signal to the system in order to determine whether the system is operating properly.

Claims

1. A time stress measurement device for sensing and processing data regarding an electronic or mechanical system comprising:

environmental data collecting means for collecting event fault data corresponding to an event experienced by the system being measured;

event data collecting means for collecting event fault data corresponding to an event experienced by the system being measured;

processing means for time-stamping the collected environmental data with a time when the environmental data is collected, for time-stamping the collected fault data with a time when the fault data is collected, and for comparing the collected environmental data to preset environmental data thresholds and time-stamping environmental data exceeding the preset thresholds; and

storage means for storing the time-stamped environmental data and time-stamped event data.

2. A device as set forth in claim 1, further comprising a voltage comparator for measuring a fluctuation in a voltage supplied to the system being measured.

3. A device as set forth in claim 2, further comprising means for generating an interrupt signal to the processing means in response to the measured fluctuation exceeding a preset limit.

4. A device as set forth in claim 1, further comprising means for detecting environmental data corresponding to an environmental influence applied to the system being measured, when said system being measured is de-energized, and for temporarily energizing the processing means to process and store the data.

5. A device as set forth in claim 1, wherein the environmental data collecting means include a plurality of analog sensors.

6. A device according to claim 5, wherein the environmental data collecting means includes an analog to digital converter.

7. A device according to claim 1, wherein the environmental data collected by the environmental data collecting means includes at least one of the group consisting of temperature, pressure, voltage, and acceleration.

8. A device according to claim 7, wherein the processing means is further for calculating vibration from the acceleration data.

9. A device according to claim 1, wherein the processing means is further for calculating differential temperature.

10. A device according to claim 1, wherein the processing means is further for calculating differential pressure.

11. A device according to claim 1, wherein the processing means is further for calculating a change in voltage.

12. A device according to claim 1, wherein the system being measured houses the time stress measurement device.

13. A device as set forth in claim 1, wherein the processing means assigns a system BIT event code to the collected event data.

14. A device as set forth in claim 1, wherein the event data includes data corresponding to a system fault.

15. A device as set forth in claim 1, further comprising time reading means for reading real time.

16. A device as set forth in claim 15, wherein the time reading means include a real time clock.

17. A device as set forth in claim 1, wherein the storage means includes a non-volatile memory.

18. A device as set forth in claim 1, wherein the storage means includes means for storing recent environmental data, the recent environmental data including a first preselected amount of time worth of environmental data.

19. A device as set forth in claim 1, wherein the storage means includes means for storing historical data, the historical data including a second preselected amount of time worth of environmental data.

20. A device as set forth in claim 1, wherein the storage means include means for storing peak environmental data, the peak environmental data including time-stamped peak measurements of at least one of the group consisting of temperature, differential temperature, pressure, differential pressure, voltage, differential voltage, acceleration, shock, and vibration.

21. A device as set forth in claim 1, wherein the storage means includes means for storing event signature data, the event signature data including time-stamped environmental data collected before, during, and after the event data is collected.

22. A device as set forth in claim 1, wherein the processing calculates histogram data, and the storage means further comprises means for storing the histogram data.

23. A device as set forth in claim 1, wherein the storage means is further for storing environmental data exceeding the preset environmental data thresholds.

24. A device as set forth in claim 1, further comprising means for self-testing the device.

25. A device as set forth in claim 1, further comprising communication means for communicating the data stored in the storage means.

26. A maintenance processor/time stress measurement device for sensing and processing data regarding an electronic or mechanical system comprising:

environmental data collecting means for collecting environmental data corresponding to a plurality of environmental data corresponding to a plurality of environmental influences applied to a system being measured;

event data collecting means for collecting event fault data corresponding to an event experienced by the system being meansured;

processing means for time-stamping the collected environmental data with a time when the environmental data is collected, for time-stamping the collected event data with a time when the event data is collected, and for comparing the collected environmental data to preset environmental data exceeding the preset thresholds;

testing means for testing the system being measured to determine whether it is operating according to selected parameters; and

storage means for storing the time-stamped environmental data and time-stamped event data.

27. A device as set forth in claim 26, wherein the testing means include means for supplying a test signal to the system being measured, and receiving a response to the test signal generated by the system being measured.

28. A device as set forth in claim 27, wherein the test signal is a digital test code.

29. A device as set forth in claim 27, wherein the test signal is an analog signal.

30. A device as set forth in claim 27, wherein the processing means analyzes the system response to determine whether the system being measured is operating in accordance with the selected parameters.

31. A device as set forth in claim 27, wherein the storage means stores response data corresponding to the response.

32. A method of measuring events and stresses on an electronic or mechanical system, comprising the steps of:

collecting event fault data corresponding to an event experienced by the system;

time-stamping the environmental data with a time when the environmental data is collected;

comparing the environmental data to preset environmental data thresholds;

time-stamping the environmental data exceeding the present thresholds with a time when the environmental data exceeds the preset threshold;

time-stamping the event data with a time when the event data is collected; and

storing the time-stamped environmental data and time-stamped event data.

33. A method as set forth in claim 32, wherein the step of collecting environmental data includes a step of converting analog environmental data to digital environmental data.

34. A method as set forth in claim 32, wherein the step of time-stamping includes time-stamping the data with both a time and a date.

35. A method as set forth in claim 32, wherein the step of collecting environmental data includes collecting at least one of the group consisting of temperature, pressure, voltage, and acceleration.

36. A method as set forth in claim 35, further including a step of calculating vibration.

37. A method as set forth in claim 32, further including a step of calculating differential temperature.

38. A method as set forth in claim 32, further including a step of calculating differential pressure.

39. A pressure method as set forth in claim 32, further including a step of calculating change in voltage.

40. A method as set forth in claim 32, wherein the step of collecting event data includes a step of assigning a system BIT event code to the event data.

41. A method as set forth in claim 32, wherein the step of storing includes storing a first amount of time worth of environmental data in a recent data file.

42. A method as set forth in claim 32, wherein the step of storing includes storing a second amount of time worth of historical data in a historical data file.

43. A method as recited in claim 32, wherein the step of storing includes storing environmental data before, during, and after event data is collected in an event signature file.

44. A method as set forth in claim 32, further comprising a step of calculating histogram data, and storing the histogram data in a histogram file.

45. A method as set forth in claim 32, further comprising the step of communicating the stored data.

46. A method as set forth in claim 32, further comprising a step of testing the system.

47. A method as set forth in claim 46, wherein the testing step includes the steps of supplying a selected test signal to the system, receiving the system'"'"'s response to the selected test signal, and analyzing the response to determine whether the system is operating according to selected parameters.

48. A method as set forth in claim 47, wherein the step of supplying a test signal includes supplying a digital test code.

49. A method as set forth in claim 47, wherein the step of supplying a test signal includes supplying an analog test signal.

50. A method as set forth in claim 47, further comprising a step of storing data corresponding to the response.