Method and Device for Predicting a Life Expectancy of a Product Containing a Plurality of Components

• US 20090119029A1
• Filed: 11/25/2005
• Published: 05/07/2009
• Est. Priority Date: 12/16/2004
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Hahn, Christopher, Wostradowski, Uwe, Muench, Reinhold, Durdevic, Ivica, Rupp, Thomas, Breibach, Joerg, Duerr, Johannes, Jaeckle, Philippe, Chabaud, Antoine, Ehrhardt, Hendrik, Becker, Rolf, Voigtlaender, Klaus
• Granted Patent: US 7,831,396 B2
• Time in Patent Office: Days
• US Class Current: 702/34
• CPC Class Codes: G05B 19/4065 Monitoring tool breakage, life or condition
• CPC Class Codes: G05B 2219/37253 Fail estimation as function of lapsed time of use

Abstract

A method and a device are for predicting a life expectancy of a product, which includes at least two components. The life expectancy is ascertained as a function of an assumed field loading of the product. The components of the product are acted upon by different loadings and are operated, in each instance, at the different loadings until they fail. An end-of-life curve of the component is recorded on the basis of the load-dependent failure times of a component. An EOL curve of the product is ascertained such that at the different loadings, it includes the EOL curve of the components which has, in each instance, the shortest failure time at the corresponding loading. The anticipated service life of the product is determined as a functional value of the EOL curve of the product as a function of the predefined loading of the product.

Claims

1-13. -13. (canceled)

14. A method for predicting a life expectancy of a product, having at least two components, as a function of a specifiable loading of the product, comprising:

acting upon the components of the product by different loadings;

operating each component at the different loadings until failure;

storing obtained failure times for each component as a function of the loading;

recording a corresponding end-of-life (EOL) curve of the component as a function of the load-dependent failure time of the component;

ascertaining an EOL curve of the product, so that at the different loadings, it includes the EOL curve of the components which has a shortest failure time at the corresponding loading; and

determining an anticipated service life of the product as a functional value of the EOL curve of the product as a function of the predefined loading of the product.

15. The method according to claim 14, wherein the method is used for producing a reliability verification for the product, and it is checked if the EOL curve of the product is above a specifiable loading for a specifiable period of time, and if this is so, the reliability verification for the product is considered to be produced.

16. The method according to claim 14, wherein the EOL curves of the components are extrapolated to lower loadings.

17. The method according to claim 14, wherein the EOL curves of the components are interpolated between discrete values of the failure times at specific loadings at which the EOL curves are recorded.

18. The method according to claim 14, wherein the loading is at least one of (a) a specific, absolute operating temperature of the component and (b) a temperature fluctuation of a particular amplitude within a specific period of time.

19. The method according to claim 18, wherein at each loading class, a distance of a duration of a predefined loading of a component to a corresponding value on the EOL curve of the component is determined and summed up according to Palmgren-Miner.

20. The method according to claim 18, wherein within the scope of a thermal loading of the product, an accelerated reliability verification is conducted at a specific temperature above a specifiable field loading, for a specific period of time less than a duration of a field loading;

the specific temperature and the specific period of time being adjusted to one another such that a mechanical loading of the product and a thermomechanical loading of the product are accelerated by approximately a same factor.

21. The method according to claim 14, wherein an EOL curve of a component includes at least two points that result from the failure times of the component at different loadings.

22. A device for predicting a life expectancy of a product, that includes at least two components, as a function of a specifiable loading of the product, comprising:

a device configured to load an end-of-life curve of at least two of the components, the EOL curves having been recorded beforehand as a function of ascertained, load-dependent failure times of the components;

a device configured to ascertain an EOL curve of the product, so that at different loadings, it includes the EOL curve of the components which has a shortest failure time at the corresponding loading; and

a device configured to determine an anticipated service life of the product as a functional value of the EOL curve of the product as a function of the predefined loading of the product.

23. The device according to claim 22, wherein the at least two EOL curves for the components have been recorded beforehand as a function of ascertained, load-dependent failure times of the components.

24. The device according to claim 23, wherein the at least two EOL curves for the components have been recorded by a manufacturer of the component.

25. The device according to claim 22, wherein the device is configured to produce a reliability verification for the product and includes a device configured to check if the EOL curve of the product is above a specifiable loading for a specifiable period of time, and if this is so, the reliability verification for the product is considered to be produced.

26. A computer-readable storage medium for storing a computer program having a plurality of program codes for implementing, when the program codes are executed on a computer, a method for predicting a life expectancy of a product, having at least two components, as a function of a specifiable loading of the product, the method including:

acting upon the components of the product by different loadings;

operating each component at the different loadings until failure;

storing obtained failure times for each component as a function of the loading;

recording a corresponding end-of-life (EOL) curve of the component as a function of the load-dependent failure time of the component;

ascertaining an EOL curve of the product, so that at the different loadings, it includes the EOL curve of the components which has a shortest failure time at the corresponding loading; and

determining an anticipated service life of the product as a functional value of the EOL curve of the product as a function of the predefined loading of the product.