Method and device for checking a sensor signal

• US 20100060296A1
• Filed: 09/14/2007
• Published: 03/11/2010
• Est. Priority Date: 10/13/2006
• Status: Active Grant

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Continental Automotive GmbH (Continental AG)
• Inventors: Preis, Herbert, Resch, Christoph, Kretschmann, Matthias, Jiang, Zheng-Yu
• Granted Patent: US 8,797,047 B2
• Time in Patent Office: Days
• US Class Current: 324/613
• CPC Class Codes: G01D 18/00 Testing or calibrating apparatus or arrangements provided for in groups G01D1/00 - G01D15/00
• CPC Class Codes: G01D 2218/10 Testing of sensors or measuring arrangements
• CPC Class Codes: G01R 23/20 Measurement of non-linear distortion
• CPC Class Codes: G01R 31/2829 Testing of circuits in sensor or actuator systems testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844

Abstract

Depending on a sensor signal, a noise signal which suppresses a useful signal spectrum of the sensor signal is determined by filtering using a filter. A noise variable, which is a measure of a noise of the sensor signal, is determined depending on the noise signal. An error of the sensor signal is identified depending on the noise variable determined.

Claims

1. A method of checking a sensor signal of a sensor, comprising the steps of:

in dependence upon the sensor signal, determining a noise signal by means of filtering with a filter that suppresses a useful signal spectrum of the sensor signal,

in dependence upon the noise signal, determining a noise quantity, which is a measure of a noise of the sensor signal, and

detecting an error of the sensor signal in dependence upon the determined noise quantity.

2. The method according to claim 1, wherein the filter is a high-pass filter.

3. The method according to claim 1, wherein the error of the sensor signal is detected if the determined noise quantity is lower than a defined lower threshold value or greater than a defined upper threshold value.

4. The method according to claim 3, wherein the defined lower threshold value is at least one of about 0 to 0.5 times and the defined upper threshold value is about 1.5 to 4 times a noise value of the sensor.

5. The method according to claim 1, wherein the noise quantity is determined as a standard deviation of the noise signal.

6. The method according to claim 5, wherein the standard deviation for an actual time step is determined recursively in dependence upon a first value, which was determined as the standard deviation for a preceding time step, and a second value, which represents the noise signal at the actual time step.

7. The method according to claim 6, wherein for determining the standard deviation for the actual time step the first value and the second value are weighted differently in dependence upon a defined parameter.

16. The method according to claim 1, wherein the step of suppressing is performed by a high-pass filter.

17. The method according to claim 1, wherein upon detection of an error an error counter is incremented.

18. The method according to claim 17, wherein said error counter is reset or decremented after a predefined period of time.

19. The method according to claim 17, wherein said step of indicating an error is performed id said error counter exceeds a predefined threshold.

20. The method according to claim 19, wherein said threshold is defined in dependence upon a noise value of said sensor.

8. A device for checking a sensor signal of a sensor, which device is operable

to determine a noise signal in dependence upon the sensor signal by means of filtering with a filter that suppresses a useful signal spectrum of the sensor signal,

to determine a noise quantity, which is a measure of a noise of the sensor signal, in dependence upon the noise signal and

to detect an error of the sensor signal in dependence upon the determined noise quantity.

9. The device according to claim 8, wherein the filter is a high-pass filter.

10. The device according to claim 8, wherein the error of the sensor signal is detected if the determined noise quantity is lower than a defined lower threshold value or greater than a defined upper threshold value.

11. The device according to claim 10, wherein the defined lower threshold value is at least one of about 0 to 0.5 times and the defined upper threshold value is about 1.5 to 4 times a noise value of the sensor.

12. The device according to claim 8, wherein the noise quantity is determined as a standard deviation of the noise signal.

13. The device according to claim 12, wherein the standard deviation for an actual time step is determined recursively in dependence upon a first value, which was determined as the standard deviation for a preceding time step, and a second value, which represents the noise signal at the actual time step.

14. The device according to claim 13, wherein for determining the standard deviation for the actual time step the first value and the second value are weighted differently in dependence upon a defined parameter.

15. A method of checking a sensor signal of a sensor, comprising the steps of:

determining a noise signal in dependence upon the sensor signal by suppressing a useful signal spectrum of the sensor signal,

determining in dependence upon the sensor signal a noise quantity, which is a measure of a noise of the sensor signal,

detecting an error of the sensor signal in dependence upon the determined noise quantity, and

indicating the error to a user.