Method of Making a Decision on the Status of a Mechanical System Using Input and Response Data Acquired In Situ

• US 20080249734A1
• Filed: 06/13/2008
• Published: 10/09/2008
• Est. Priority Date: 04/29/2005
• Status: Active Grant

• Current Assignee: University of Vermont & State Agricultural College
• Original Assignee: University of Vermont & State Agricultural College
• Inventors: Frolik, Jeffrey L.
• Granted Patent: US 7,831,403 B2
• Time in Patent Office: Days
• US Class Current: 702/113
• CPC Class Codes: B60G 2206/90 Maintenance
• CPC Class Codes: B60G 2600/042 Monitoring means
• CPC Class Codes: B62K 25/04 for mounting axles resiliently on cycle frame or fork for sidecars, forecars or the like B62K27/06
• CPC Class Codes: G01M 13/028 Acoustic or vibration analysis
• CPC Class Codes: G01M 17/04 Suspension or damping
• CPC Class Codes: G07C 5/008 communicating information to a remotely located station transmission systems for measured values G08C

Abstract

An in-situ monitoring system is engaged with a mechanical system for which it is desired to assess or monitor the in-situ performance of the mechanical system. The in-situ monitoring system includes at least one input sensor and at least one output sensor for collecting data corresponding, respectively, to input into, and output from, the mechanical system. The monitoring system also includes an analyzer that utilizes the input and output data to generate an in-situ response representation of the mechanical system. The in-situ representation may be used to make a decision regarding the status of the mechanical system, e.g., to replace all or part of it, to adjust it or to do nothing. In one embodiment, the analyzer is programmed to adapt to the operating conditions of the mechanical system by automatically selecting which one of a number of target representations should be used to characterize the in-situ representation.

Claims

1. A method of investigating performance of a mechanical system operating under in-situ operating conditions, wherein the mechanical system is responsive to an operating input loading so as to have an operating response to the operating input loading, the method comprising:

collecting, via a first sensor, input load data corresponding the operating input loading, wherein the first sensor is not an operational part of the mechanical system;

collecting, via a second sensor, response data representing the operating response, wherein the second sensor is not an operational part of the mechanical system;

causing a machine to generate an in-situ representation of the mechanical system as a function of the input load data and the operating response data;

obtaining a target-response representation of the mechanical system; and

comparing the target-response representation and the in-situ representation with one another so as to determine the performance of the mechanical system.

2. A method according to claim 1 wherein the mechanical system has a load-input side and a load-response side and the method further comprises attaching, for the substantially the sole purpose of performing the method, the first sensor to the load-input side and the second sensor to the load-response side.

3. A method according to claim 2, wherein said attaching of the first and second sensors includes attaching first and second accelerometers.

4. A method according to claim 1, wherein the mechanical system has a tuning, and the method further comprises adjusting the timing based on said comparing of the target-response representation and the in-situ representation with one another.

5. A method according to claim 1, wherein the mechanical system has a replaceable component that affects the performance of the mechanical system, and the method further comprises replacing the replaceable component based on said comparing of the target-response representation and the in-situ representation with one another.

6. A method according to claim 1, wherein said causing of the machine to generate the in-situ representation comprises causing the machine to utilize multidimensional signal processing techniques.

7. A method according to claim 1, wherein the step of comparing the target-response representation and the in-situ representation with one another so as to determine the performance of the mechanical system is performed by the machine.

8. A method according to claim 1, further comprising displaying the in-situ representation and the target-response representation simultaneously with one another so as to assist a user in making a decision regarding the status of the performance of the mechanical system.

9. A method according to claim 1, wherein said cause of the machine to generate said in-situ representation comprises causing the machine to generate a frequency response graph.

10. A method of monitoring performance of a mechanical system under in-situ operating conditions over an extended period, wherein the mechanical system is responsive to an operating input loading so as to have an operating response to the operating input loading, comprising:

at a plurality of spaced intervals over the extended period;

collecting, via a first sensor, input load data corresponding to operating input loading, wherein the first sensor is not an operational part of the mechanical system;

collecting, via a second sensor, response data representing the operating response, wherein the second sensor is not an operational part of the mechanical system;

causing a machine to generate an in-situ diagnostic representation of the operating response as a function of the input load data and the output response data; and

assessing said in-situ diagnostic representation so as to monitor the performance of said mechanical system.

11. A method according to claim 10, further comprising obtaining a baseline-response representation of the mechanical system, said assessing of the ill-situ diagnostic representation comprising comparing the in-situ diagnostic representation and the baseline-response representation with one another so as to determine a difference between the in-situ diagnostic representation and the baseline-response representation.

12. A method according to claim 10, wherein the mechanical system has a load-input side and a load-response side and the method further comprises attaching, for the substantially the sole purpose of performing the method, the first sensor to the load-input side and the second sensor to the load-response side.

13. A method according to claim 12, wherein said attaching of the first and second sensors includes attaching first and second accelerometers.

14. A method according to claim 10, further comprising, at each of the plurality of intervals, temporarily placing the first and second sensors in operative relationship with said mechanical system and subsequently removing the first and second sensors.

15. A method according to claim 10, wherein said causing of the machine to generate said in-situ diagnostic representation comprises causing the machine to generate at least one of the following:

an impulse response, a frequency-domain transfer function, frequency response function and digital filter coefficients.

16. A method of assessing the performance of a mechanical system having an input loading and a response to the input loading, comprising:

storing, via a first signal from a first sensor placed in operative relation to the mechanical system, input data corresponding to the input loading, wherein the first sensor is not an operational part of the mechanical system;

storing, via a second signal from a second sensor placed in operative relation to the mechanical system, response data corresponding to the response, wherein the second sensor is not an operational part of the mechanical system;

automatically generating an in-situ response representation as a function of the input data and the response data;

automatically selecting one of a plurality of stored target-response representations as a function of the input data;

automatically making a comparison of the in-situ response representation to the one of the plurality of stored target-response representations for a purpose other than controlling the response of the mechanical system; and

outputting to a user information concerning said comparison.

17. A method according to claim 16, wherein said outputting of the information includes displaying a result of said comparison on a display.

18. A method according to claim 16, wherein said automatic generating of the in-situ response representation comprises generating a frequency response spectrum.

19. A method according to claim 16, wherein said storing of the input data comprises storing input acceleration data and said storing of the response data comprises storing response acceleration data.

20. A method according to claim 16, wherein each of the plurality of target response representations is an acceptable limits envelope.

21. A method according to claim 16, wherein the mechanical system includes a damper.

22. A computer-readable medium containing computer-executable instructions for performing a method of assessing the performance of a mechanical system having an input loading and a response to the input loading, the computer-executable instructions comprising:

a first set of computer-executable instructions for storing, via a first signal from a first sensor placed in operative relation to the mechanical system, input data corresponding to the input loading, wherein the first sensor is not an operational part of the mechanical system;

a second set of computer-executable instructions for storing, via a second signal from a second sensor placed in operative relation to the mechanical system, response data corresponding to the response, wherein the second sensor is not an operational part of the mechanical system;

a third set of computer-executable instructions for automatically generating an in-situ response representation as a function of the input data and the response data;

a fourth set of computer-executable instructions for automatically selecting one of a plurality of stored target-response representations as a function of the input data;

a fifth set of computer-executable instructions for automatically making a comparison of the in-situ response representation to the one of the plurality of stored target-response representations for a purpose other than controlling the response of the mechanical system; and

a sixth set of computer-executable instructions for outputting to a user information concerning said comparison.

23. A computer-readable medium according to claim 22, wherein said sixth set of instructions includes a set of instructions for displaying a result of the comparison on a display.

24. A computer-readable medium according to claim 22, wherein said third set of instructions comprises instructions for generating a frequency response spectrum.

25. A system for assessing the performance of a mechanical system having a mechanical input and a response to the input, the system comprising:

a first sensor for collecting input data corresponding to the mechanical input of the mechanical system;

a second sensor for collecting response data corresponding to the response of the mechanical system;

at least one memory for storing the input data and the response data;

the at least one memory containing at least one stored target-response representation; and

an analyzer programmed to at least;

store in said at least one memory said input data and said response data;

automatically generate an in-situ response representation as a function of the input data and the response data;

automatically compare the in-situ response representation to the stored target-response representation for a purpose other than controlling the response of the mechanical system; and

outputting to a user information concerning the comparison.

26. A system according to claim 25, wherein said at least one memory contains a plurality of stored target-response representations and said analyzer is further programmed to automatically select one of said plurality of stored target-response representations as a function of said input data.

27. A system according to claim 26, wherein each of said plurality of stored target-response representations is an acceptable-limits envelope.

28. A system according to claim 25, further comprising a display, said analyzer further programmed to display a result of said comparison on said display.

29. A system according to claim 28, wherein said analyzer is further programmed to simultaneously display said in-situ response representation and said stored target-response representation on said display.