Method and apparatus for assessing the residual life of a sensor unit

• US 20090164166A1
• Filed: 12/10/2008
• Published: 06/25/2009
• Est. Priority Date: 12/19/2007
• Status: Active Grant

• Current Assignee: AVL List GmbH (List Privatstiftung)
• Original Assignee: AVL List GmbH (List Privatstiftung)
• Inventors: Rzehorska, Martin, Mayrhofer, Norbert, Harms, Klaus-Christoph, Teichmann, Rudiger
• Granted Patent: US 7,840,362 B2
• Time in Patent Office: Days
• US Class Current: 702/116
• CPC Class Codes: G01M 15/042 by monitoring a single specific parameter not covered by groups G01M15/06 - G01M15/12

Abstract

The life of a sensor unit is very strongly dependent on the loading of the sensor unit during use. The life of a sensor unit is generally specified in a number of loading cycles, however, which does not take into consideration the loading of the sensor unit. The invention therefore specifies a method and apparatus for assessing the residual life of a sensor unit which takes into consideration the actual loading of the sensor unit and therefore the residual life of the sensor unit (10) can be estimated more precisely by virtue of a damage factor (S) being determined for the loading of a loading cycle (B) and the loading cycle (B) being weighted therewith.

Claims

1. A method for assessing the residual life (R) of a sensor unit (10), which is fitted on a cyclically operating machine and is intended for a certain number of loading cycles (B), comprising the steps of:

detecting loading of the sensor unit by the machine in a loading cycle (B),

determining a damage factor (S) for the sensor unit (10) as a function of the detected loading by means of a damage model (9) of the sensor unit (10) for the loading cycle (B), and

weighing the loading cycle (B) with the respectively determined damage factor (S) in order to assess the residual life (R).

2. The method according to claim 1, wherein only a measured variable detected by the sensor unit (10) is used to determine the damage factor (S).

3. The method according to claim 1, wherein each loading cycle (B) is weighted individually and the residual life (R) is determined continuously.

4. The method according to claim 1, wherein each loading cycle (B) is weighted individually and the residual life (R) is determined after a certain number of loading cycles (B) or a specific time.

5. The method according to claim 1, wherein a frequency (H) of the occurrence of a specific loading state in loading cycles (B) is counted and the counted frequency (H) is weighted with the damage factor (S) determined for the loading cycle (B) in order to determine the residual life (R).

6. The method according to claim 5, wherein the weighted loading cycles (B) or a weighted frequency (H) of the loading cycles (B) is subtracted from a specified loading cycle number (L).

7. The method according to claim 5, wherein the weighted loading cycles (B) or the weighted frequency (H) of the loading cycles (B) is standardized with a predetermined value, preferably the specified number (L) of permissible loading cycles.

8. The method according to claim 1, wherein the sensor unit (10) is categorized into permissible use types using the determined residual life (R).

9. The method according to claim 1, wherein a calibration interval or a self-testing interval of the sensor unit (10) is determined using the determined residual life (R).

10. An apparatus for assessing the residual life (R) of a sensor unit (10), which is fitted on a cyclically operating machine and is intended for a certain number of loading cycles (B), comprising an assessment unit (6) and a damage model (9) a damage factor (S) being determined in the assessment unit as a function of the loading of the sensor unit (10) for a loading cycle (B) using the damage model (9), and the loading cycle (B) is weighted with the damage factor (S) in order to assess the residual life (R).

11. The apparatus according to claim 10, wherein the assessment unit (6) is in the sensor unit (10).

12. The apparatus according to claim 10, wherein the assessment unit (6) is in an evaluation unit (8), which is connected to the sensor unit (10).

13. An apparatus according to claim 10, wherein the assessment unit (6) is in a control unit (7), which is connected to the evaluation unit (8), which is connected to the sensor unit (10).

14. An apparatus according to claim 10, including an output device (15) for outputting the residual life (R) of the sensor unit (10) on the sensor unit (10), on the evaluation unit (8) or on the control unit (7).

15. An apparatus according to claim 10, including a sensor management unit (14) in which the sensor unit (10) together with the associated determined residual life (R) is managed.

16. Internal combustion engine with a sensor unit (10) for detecting a measured motor variable and with an apparatus for assessing the residual life (R) of the sensor unit (10) according to claim 10.