Limit based threshold estimation for prognostics and health management

Patent metadata

Field	Value
Publication number	US-10126209-B2
Application number	US-201214651181-A
Country	US
Kind code	B2
Filing date	Dec 18, 2012
Priority date	Dec 18, 2012
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

According to an embodiment, a method of monitoring the operation of a device includes determining a plurality of operational parameters that are indicative of an operation condition of the device. A difference between each operational parameter and a corresponding limit on that parameter is determined. Each limit indicates a value of the corresponding operational parameter that corresponds to an undesirable operation condition of the device. An action index is determined based on at least a smallest one of the determined differences. A determination is made whether the action index is within a range corresponding to desirable operation of the device.

First claim

We claim:

1. A method of operating a fuel cell system, the method comprising:
receiving, by one or more hardware processors and from a plurality of sensors communicatively coupled to the fuel cell system, sensor information indicative of a plurality of operational conditions of the fuel cell system;
for each of multiple operational parameters associated with the indicated plurality of operational conditions, determining, by the one or more processors and based at least in part on the received sensor information, a difference between an observed value for the operational parameter and a corresponding limit for the operational parameter, the corresponding limit indicating one or more undesirable values for the operational parameter;
generating, by the one or more processors and based at least in part on a smallest one of the determined differences, one or more action indexes for the fuel cell system;
determining, by the one or more processors, whether at least one of the one or more action indexes is not within an acceptable range; and
responsive to determining that the at least one action index is not within the acceptable range, initiating, by the one or more processors, one or more corrective actions regarding the fuel cell system.

2. The method of claim 1 , wherein determining the difference between the observed value for the operational parameter and the corresponding limit for the operational parameter includes determining a Euclidean distance of the operational parameter from the corresponding limit, and wherein the determined Euclidean distance is the determined difference.

3. The method of claim 2 , wherein determining the difference between the observed value for the operational parameter and the corresponding limit for the operational parameter includes determining a square of the Euclidean distance for the operational parameter.

4. The method of claim 2 , wherein generating the one or more action indexes includes:
identifying the operational parameter having the smallest determined difference between the observed value and the corresponding limit;
modifying the identified operational parameter by adding a weighted version of the determined Euclidean distance for the identified operational parameter to the observed value for the identified operational parameter; and
determining a modified difference between the modified operational parameter and the corresponding limit.

5. The method of claim 2 , wherein generating the one or more action indexes includes:
for each of the multiple operational parameters, modifying the operational parameter by adding a weighted version of the determined Euclidean distance for the operational parameter to the observed value for the operational parameter, and determining a modified difference between the modified operational parameter and the corresponding limit; and
generating a matrix of the modified differences.

6. The method of claim 5 , wherein generating the one or more action indexes includes generating a product of:
the matrix of the modified differences;
a principal component vector matrix that includes predetermined operational parameter values corresponding to desirable operation of the fuel cell system;
a diagonal matrix of principal component Eigen values;
a transpose of the principal component vector matrix; and
a transpose of the matrix of the modified differences.

7. The method of claim 2 , wherein the at least one action index comprises a shutdown index, wherein determining whether the shutdown index is within the acceptable range includes determining that the shutdown index is not within the acceptable range, and wherein the one or more corrective actions includes initiating a shutdown operation of the fuel cell system.

8. The method of claim 1 , wherein determining whether at least one of the one or more action indexes is not within an acceptable range includes:
determining a respective lower limit on an acceptable value for each of the one or more action indexes; and
determining whether any of the one or more action indexes has a value less than the determined respective lower limit.

9. The method of claim 1 , wherein determining whether at least one of the one or more action indexes is not within an acceptable range includes:
determining a respective higher limit on an acceptable value for each of the one or more action indexes; and
determining whether any of the one or more action indexes has a value greater than the determined respective higher limit.

10. A hardware device control system, comprising:
a plurality of detectors that provide respective indications of multiple operational parameters that are indicative of one or more operational conditions of a hardware device;
a user interface that, in operation, provides information related to at least one of the one or more operational conditions of the hardware device; and
a hardware processor that is communicatively coupled to the plurality of detectors and to the user interface and that, in operation, performs a method that includes to:
determine, for each of the multiple operational parameters, a difference between an observed value for the operational parameter and a corresponding limit for the operational parameter, wherein the corresponding limit identifies one or more undesirable values for the operational parameter;
generate an action index based at least in part on a smallest one of the multiple determined differences;
determine whether the generated action index is within a defined acceptable range corresponding to desirable operation of the hardware device; and
in response to a determination that the generated action index is not within the defined acceptable range, initiate one or more corrective actions, wherein to initiate the one or more corrective actions includes presenting, via the user interface and one or more electronic signals generated by the hardware processor, an indication that the generated action index is not within the defined acceptable range.

11. The system of claim 10 , wherein to determine the difference between the observed value and the corresponding limit includes to determine a Euclidean distance of the observed value from the corresponding limit and wherein the determined Euclidean distance is the determined difference.

12. The system of claim 11 , wherein to determine the difference between the observed value and the corresponding limit includes to determine a square of the Euclidean distance for the operational parameter.

13. The system of claim 10 , wherein to generate the action index includes to:
identify the operational parameter having the smallest determined difference between the observed value for the operational parameter and the corresponding limit for the operational parameter;
modify the identified operational parameter by adding a weighted version of the determined distance for the identified operational parameter to the observed value for the identified operational parameter; and
determine a modified difference between the modified operational parameter and the corresponding limit.

14. The system of claim 13 , wherein the method further includes to:
for each of the multiple operational parameters, modify the operational parameter by adding a weighted version of the determined distance for the operational parameter to the observed value for the operational parameter, and determine a modified difference for the operational parameter; and
generate a matrix of the modified differences.

15. The system of claim 14 , wherein to generate the action index includes to multiply:
the matrix of the modified differences;
a p

Assignees

• Audi Ag

Inventors

• Ramaswamy Sitaram
• Boopathy Mothivel Mummudi

Classifications

• G05B23/0235 Primary

  based on a comparison with predetermined threshold or range, e.g. "classical methods", carried out during normal operation; threshold adaptation or choice; when or how to compare with the threshold · CPC title

• H01M8/0432

  Temperature; Ambient temperature · CPC title

• H01M8/04574

  Current · CPC title

• H01M8/04544

  Voltage · CPC title

• G05B2219/2668

  Fuel cells · CPC title