Method and apparatus for providing a polynomial based virtual age estimation for remaining lifetime prediction of a system

• US 7,299,162 B2
• Filed: 12/14/2001
• Issued: 11/20/2007
• Est. Priority Date: 12/14/2000
• Status: Expired due to Fees

• Current Assignee: Siemens Corp. (Siemens AG)
• Original Assignee: Siemens Corporate Research Incorporated (Siemens AG)
• Inventors: Loecher, Markus, Darken, Christian
• Primary Examiner(s): FERRIS III, FRED O
• Application Number:
  US10/017,014
• Publication Number:
  US 20030014226A1
• Time in Patent Office: 2,167 Days
• Field of Search: 703/2, 700/21, 700/52, 714/1, 714/41, 702/34
• US Class Current: 703/2
• CPC Class Codes: G06Q 10/06 Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling

Abstract

A method for providing a virtual age estimation for predicting the remaining lifetime of a device of a given type, comprises the steps of monitoring a predetermined number of significant parameters of respective ones of a training set of devices of the given type, the parameters contributing respective wear increments, determining coefficients of a multivariate Hermite polynomial for modeling the wear increments determined from the training set operated to failure and whereof the respective virtual ages are normalized substantially to a desired norm value, deriving from the multivariate Hermite polynomial a formula for virtual age of a device of the given type, and applying the formula to the significant parameters from a further device of the given type for deriving wear increments for the further device.

Claims

1. A method for providing a virtual age estimation for predicting the remaining lifetime of a device of a given type, comprising the steps of:

monitoring a predetermined number of significant parameters of respective ones of a training set of devices of said given type, said parameters contributing respective wear increments;

determining coefficients of a multivariate Hermite polynomial for modeling said wear increments determined from said training set operated to failure and whereof the respective virtual ages are normalized substantially to a desired norm value;

deriving from said multivariate Hermite polynomial a formula for virtual age of a device of said given type; and

applying said formula to said significant parameters from a further device of the said given type for deriving wear increments for said further device.

2. A method for providing a virtual age estimation as recited in claim 1, including a step of cumulating said further device so as to derive a virtual age estimation for said further device.

3. A method for providing a virtual age estimation as recited in claim 1, including a step of selecting said predetermined number of significant parameters by selecting a number thereof so as to minimize deviations of said virtual ages from said normalized virtual age.

4. A method for providing a virtual age estimation for devices of a given type by predicting the remaining lifetime of a further device of said given type by computing wear increments, comprising the steps of:

collecting data on parameters contributing wear increments in a training set of sample devices until failure, said sample devices being similar to said given device;

modeling a wear increment by a multivariate Hermite polynomial of degree k;

computing the sum of increments for individual sample devices in said training set to obtain a virtual age therefore, said virtual age being normalized substantially to a convenient normalized virtual age; and

determining coefficients of said multivariate Hermite polynomial in a supervised training phase of said sample devices in said training set for said normalized virtual age; and

deriving incremental wear data for a further device, similar to said sample devices, by utilizing device data for said further device in conjunction with said coefficients of said multivariate Hermite polynomial determined in the preceding step.

5. A method for providing a virtual age estimation for devices as recited in claim 4, including a step of cumulating said incremental wear data to derive a virtual age for said further device.

6. A method for providing a virtual age estimation for devices as recited in claim 4, wherein said step of determining coefficients of said multivariate Hermite polynomial comprises a step of optimizing said determining by utilizing Ridge regression.

7. A method for providing a virtual age estimation for devices as recited in claim 6, wherein said step utilizing Ridge regression includes a step of optimizing by cross validation between devices in a subset of said training set and the remainder of devices in said training set.

8. A method for providing a virtual age estimation for devices as recited in claim 4, wherein said step of determining coefficients of said multivariate Hermite polynomial includes a step of optimizing said coefficients for reducing deviations of said virtual ages from said normalized virtual age.

9. A method for providing a virtual age estimation for devices as recited in claim 6, wherein said step of optimizing said coefficients includes a step of minimizing the sum of least squares of said deviations.

10. A method for providing a virtual age estimation for devices by predicting the remaining lifetime of a given device by computing wear increments, comprising the steps of:

modeling wear increments by a Hermite polynomial based on selected wear parameters which contribute wear increments for said devices;

adjusting coefficients of said polynomial in accordance with data derived in a training set of such devices for deriving an equation for increments of virtual age for each device in said training set, said virtual ages being normalized substantially to a desired standard value; and

applying said equation to said selected wear parameters of a further device similar to devices in said training set for computing wear increments for said further device.

11. A method for providing a virtual age estimation for devices as recited in claim 10, including a step of cumulating said wear increments for said further device for computing a virtual age for said further device.

12. A method for providing a virtual age estimation for devices as recited in claim 10, wherein said step of determining coefficients of said multivariate Hermite polynomial comprises a step of optimizing said determining by utilizing Ridge regression.

13. A method for providing a virtual age estimation for devices as recited in claim 12, wherein said step utilizing Ridge regression includes a step of optimizing by cross validation between devices in a subset of said training set and the remainder of devices in said training set.

14. A method for providing a virtual age estimation for devices as recited in claim 10, wherein said step of determining coefficients of said multivariate Hermite polynomial includes a step of optimizing said coefficients for reducing deviations of said virtual ages from said normalized virtual age.

15. A method for providing a virtual age estimation for devices as recited in claim 14, wherein said step of optimizing said coefficients includes a step of minimizing the sum of least squares of said deviations.