General method for tracking the evolution of hidden damage or other unwanted changes in machinery components and predicting remaining useful life

• US 6,567,752 B2
• Filed: 08/15/2001
• Issued: 05/20/2003
• Est. Priority Date: 08/15/2000
• Status: Expired due to Fees

• Current Assignee: Penn State Research Foundation
• Original Assignee: Penn State Research Foundation
• Inventors: Cusumano, Joseph, Chatterjee, Anindya, Chelidze, David
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): Sun, Xiuqin
• Application Number:
  US09/930,386
• Publication Number:
  US 20020046004A1
• Time in Patent Office: 643 Days
• Field of Search: 702/116, 702/34, 702/183, 702/182, 702/35, 702/44, 702/81.22, 702/71, 702/73, 702/129, 706/45, 706/16, 514/12, 514/285, 514/315, 514/311, 514/291, 432/197, 714/26, 345/474, 73/616.6, 600/484, 180/413, 273/362
• US Class Current: 702/34
• CPC Class Codes: G01R 31/343 in operation

Abstract

A method and apparatus for determining a slowly evolving damage state in a system having a time scale separation between a fast subsystem and a slow subsystem, the method includes acquiring measurement data of a fast subsystem of said system, determining a tracking function for the system, and evaluating the tracking function using the acquired measurement data to determine a measure of the slow damage subsystem the system.

Claims

1. A method for determining a slowly evolving damage state in a system having time scale separation, said method comprising:

acquiring measurement data of a fast subsystem of said system;

determining a tracking function for said system;

evaluating said tracking function using said acquired measurement data to determine a measure of said slowly evolving damage state of said system;

reconstructing a state space of said fast subsystem using said acquired data; and

constructing a short time reference predictive model using parameters from said state space reconstruction.

2. The method of claim 1, wherein said tracking function is a short time reference model prediction error for said system.

3. The method of claim 1, comprising a step of estimating a remaining useful life of said system using said tracking function.

4. The method of claim 1, comprising a step of averaging a value of said tracking function for said system over said acquired data.

5. The method of claim 4, comprising a step of estimating a remaining useful life of said system using said averaged value of said tracking function.

6. The method of claim 5, wherein said estimate is determined using recursive filtering.

7. The method of claim 5, wherein said estimate is determined using a linear recursive filter.

8. The method of claim 5, wherein said estimate is determined using a nonlinear recursive filter.

9. The method of claim 1, wherein said method is independent of damage physics of said system.

10. The method of claim 1, wherein said slowly evolving damage state occurs on a much slower scale than a measurable characteristic of said fast system.

11. An apparatus for determining a slowly evolving damage state in a system having a time scale separation, said apparatus comprising:

means for acquiring measurement data of a fast subsystem of said system;

means for determining a tracking function for said system; and

means for evaluating said tracking function using data acquired by said means for acquiring measurement data to determine a measure of said slowly evolving damage state of said system;

wherein said apparatus reconstructs a state space of said fast subsystem using said acquired data, and said apparatus constructs a short time predictive model using a parameter from said state space reconstruction.

12. The apparatus of claim 11, wherein said tracking function is a short time reference model prediction error for said system.

13. The system of claim 11, wherein said system estimates a remaining useful life of said system using said tracking function.

14. The apparatus of claim 11, wherein said apparatus averages a value of said tracking function for said system over said acquired data.

15. The apparatus of claim 14, wherein said apparatus estimates a remaining useful life of said system using said averaged value of said tracking function.

16. The apparatus of claim 15, wherein said estimate is determined using recursive filtering.

17. The apparatus of claim 15, wherein said estimate is determined using a linear recursive filter.

18. The apparatus of claim 15, wherein said estimate is determined using a nonlinear recursive filter.

19. The apparatus of claim 15, wherein said apparatus determines said slowly evolving damage state independently of damage physics of said system.

20. A storage medium having computer readable program instructions embodied therein for determining a slowly evolving damage state in a system having time scale separation, said storage medium comprising:

program instructions for acquiring measurement data of a fast subsystem of said system;

program instructions for determining a tracking function for said system;

program instructions for evaluating said tracking function using said acquired measurement data to determine a measure of said slowly evolving damage state of said system;

program instructions for reconstructing a state space of said fast subsystem using said acquired data; and

program instructions for constructing a short time reference predictive model using parameters from said state space reconstruction.