Method and device for determining a corrected offset value

• US 20030040856A1
• Filed: 05/16/2002
• Published: 02/27/2003
• Est. Priority Date: 05/16/2001
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Winner, Hermann, Urban, Werner, Lueder, Jens, Keller, Frieder
• Granted Patent: US 6,704,631 B2
• Time in Patent Office: Days
• US Class Current: 701/34
• CPC Class Codes: B60T 2250/06 Sensor zero-point adjustment; Offset compensation
• CPC Class Codes: B60T 2270/411 Offset failure
• CPC Class Codes: B60T 8/885 using electrical circuitry

Abstract

A device is for determining a corrected offset value which represents the offset of the output signal of a first vehicle sensor, the sensor determining at least one motion of a vehicle. In this device, a first arrangement is provided by which at least two offset values representing the offset of the sensor are determined by at least two different methods. In addition, for at least one of the offset values of the sensor thus determined, an error band is determined in addition to the offset value. The corrected offset value is determined as a function of the offset values determined and at least one of the error bands.

Claims

1. A device for determining a corrected offset value which represents an offset of an output signal of a first vehicle sensor, the first vehicle sensor configured to determine at least one motion of a vehicle, comprising:

a first arrangement configured to determine at least two offset values representing the offset of the first vehicle sensor by at least two different methods, and for at least one of the offset values of the first vehicle sensor thus determined, to determine an error band in addition to the offset value; and

a second arrangement configured to determine the corrected offset value as a function of the offset values thus determined and at least one of the error bands.

2. The device according to claim 1, wherein the error bands correspond to a minimum value and a maximum value for each offset value.

3. The device according to claim 2, wherein the second arrangement is configured to determine the corrected offset value of the first vehicle sensor by forming an average between a minimum of all maximum values and a maximum of all minimum values for the minimum and maximum values of the offset values of the first vehicle sensor obtained by at least two different methods.

4. The device according to claim 1, wherein the second arrangement is configured to determine the corrected offset value of the vehicle sensor by forming a weighted average between the offset values of the first vehicle sensor thus determined, the offset value having a lower weight in forming the average with an increase in a width of the error band.

5. The device according to claim 1, wherein at least one error band becomes wider, the longer it has been since the last determination of the respective offset value.

6. The device according to claim 1, wherein each of the different methods of determining offset values has a validity range assigned to it which depends on the driving status;

wherein, for those methods which are outside their validity range at the moment due to the prevailing driving status and which do not determine a quantity representing the offset value, the quantity representing the offset value determined most recently by this method within the last occurrence of this validity range is used; and

wherein the respective error band becomes wider, the longer it has been since this last valid determination of this quantity representing the offset value.

7. The device according to claim 1, wherein the first vehicle sensor is configured to detect a yawing motion of the vehicle.

8. The device according to claim 7, wherein the second arrangement is configured to determine the corrected offset value in accordance with at least one of automatic distance regulation and control adaption cruise control in the vehicle.

9. The device according to claim 1, wherein the first arrangement is configured to determine the offset values as a function of output signals of at least one additional sensor configured to detect motion of the vehicle, and the first vehicle sensor, the output signals representing at least one of wheel rotational speeds of at least one vehicle wheel, a steering wheel angle of the vehicle, and a yaw rate of the vehicle.

10. The device according to claim 1, wherein the first arrangement is configured to determine the offset value by at least one method as a function of an operating state of the vehicle prevailing at the moment, the operating state prevailing at the moment determined in accordance with at least one of a longitudinal velocity of the vehicle, a yaw rate, and a steering wheel angle.

11. The device according to claim 9, wherein the first arrangement is configured to determine the offset value by at least one method as at least one of a function of at least an analysis of one output signal of at least one of the additional sensors at at least two different points in time and a function of at least an analysis of one output signal of the first vehicle sensor at at least two different points in time;

and

wherein the first arrangement is configured to determine at least one offset value at least one of as a function of a time characteristic of the output signal of the first vehicle sensor and as a function of signals that represent the wheel rotational speeds of at least one vehicle wheel.

12. The device according to claim 1, wherein the first arrangement is configured to determination, by a first method, a first offset value by a standstill compensation method, in accordance with a negligible longitudinal velocity of the vehicle, a negligible yaw rate, and a negligible time derivation of the yaw rate;

wherein the first arrangement is configured to determine, by a second method, a second offset value by a steering angle method, in accordance with a longitudinal velocity of the vehicle and a steering wheel angle;

wherein the first arrangement is configured to determine, by a third method, a third offset value by a histogram method; and

wherein the first arrangement is configured to determine, by a fourth method, a fourth offset value by a regression method, the yaw rate calculated from differences in wheel rotational speed.

13. The device according to claim 1, wherein the second arrangement is configured to determine the corrected offset value at one of regular and irregular time intervals.

14. A method of determining a corrected offset value which represents an offset of the output signal of a first vehicle sensor, the sensor configured to determine at least one motion of a vehicle, comprising the steps of:

determining at least two offset values representing the offset of the first vehicle sensor by at least two different methods;

determining an error band in addition to the offset value for the offset values of the first vehicle sensor determined by at least one of the methods; and

determining the corrected offset value as a function of the offset values determined and at least one of the error bands.

15. The method according to claim 14, wherein the vehicle sensor is configured to detect a yawing motion of the vehicle.