Method and device for determining offset values by a histogram method

• US 6,810,311 B2
• Filed: 05/16/2002
• Issued: 10/26/2004
• 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
• Primary Examiner(s): Nguyen, Tan Q.
• Assistant Examiner(s): Tran, Dalena
• Application Number:
  US10/150,304
• Publication Number:
  US 20030074116A1
• Time in Patent Office: 894 Days
• Field of Search: 701/29, 701/36, 701/72, 701/96, 702/150, 702/151, 702/96, 303/113.2, 303/140, 303/186, 303/189, 244/164, 244/171
• US Class Current: 701/29
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60K 31/0066 responsive to vehicle path curvature
• CPC Class Codes: B60T 2250/06 Sensor zero-point adjustment; Offset compensation
• CPC Class Codes: B60T 8/172 Determining control parameters used in the regulation, e.g. by calculations involving measured or detected parameters B60T8/17551 takes precedence
• CPC Class Codes: B60W 2050/0052 Filtering, filters
• CPC Class Codes: B60W 2050/0215 Sensor drifts or sensor failures
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: B62D 6/006 using a measured or estimated road friction coefficient
• CPC Class Codes: G01D 1/14 giving a distribution function of a value, i.e. number of times the value comes within specified ranges of amplitude

Abstract

A method is for determining the offset value of the output signal of a vehicle sensor. The values of the output signal of the vehicle sensor are determined. The value range of the output signal of the vehicle sensor is divided into at least two partial ranges (intervals, classes). The values of the output signal are allocated to the partial ranges. The number of number quantities representing the values of the output signal allocated to the partial ranges is determined. The number quantities are determined by at least one low-pass filter.

Claims

1. A method of determining an offset value of an output signal of a vehicle sensor, comprising the steps of:

determining at least one value of the output signal of the vehicle sensor;

dividing a value range of the output signal of the vehicle sensor into at least two partial ranges;

allocating the value of the output signal of the vehicle sensor to the partial ranges;

determining a number of number quantities representing the values of the output signal of the vehicle sensor allocated to the partial ranges;

triggering a low-pass filter, in whose allocated partial range the value of the output signal determined at a sampling time falls, with a first input signal; and

triggering at least another low-pass filter, in whose allocated value ranges the value of the output signal determined at the same sampling time does not fall, with a second input signal, the second input signal differing from the first input signal;

wherein the number of number quantities are determined in the determining step by at least one of the low-pass filters, and

wherein the low-pass filters are allocated to the at least two partial ranges, each of the low-pass filters being configured to determine the number quantity allocated to its partial range.

2. The method according to claim 1, wherein the low-pass filter includes an exponential characteristic.

3. The method according to claim 1, further comprising the steps of:

incrementing, as a result of triggering of the low-pass filter with the first input signal, the number quantity determined by this low-pass filter; and

decrementing, as a result of the triggering of the low-pass filters with the second input signal, the number quantities determined by these low-pass filters.

4. The method according to claim 1, further comprising the steps of:

determining a first average by a first method from at least two successively determined values of the output signal of the vehicle sensor; and

allocating averages obtained by the first method to the partial ranges.

5. The method according to claim 1, wherein the vehicle sensor is configured to detect a yawing motion of the vehicle.

6. The method according to claim 5,further comprising the step of using the offset value determined for at least one of automatic distance regulation and control adaptive cruise controlling the vehicle.

7. The method according to claim 1, further comprising the step of determining the offset value by forming a weighted average in accordance with the partial range having a largest number of allocated values of the output signal and at least one adjacent interval.

8. The method according to claim 7, wherein weighting factors of the weighted average include one of linear values and quadratic values of the number quantities.

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

a first arrangement configured to determine output signals of the vehicle sensor;

a second arrangement configured to divide a value range of the output signal of the vehicle sensor into at least two partial ranges;

a third arrangement configured to allocate the values of the output signal of the vehicle sensor to the partial ranges; and

a fourth arrangement configured to determine number quantities representing a number of values of the output signal of the vehicle sensor allocated to the partial ranges, the fourth arrangement including at least one low-pass filter configured to determine the number quantities;

a triggering arrangement to trigger one of the at least one low-pass filter, in whose allocated partial range the value of the output signal determined at a sampling time falls, with a first input signal, and to trigger at least another of the at least low-pass filter, in whose allocated value ranges the value of the output signal determined at the same sampling time does not fall, with a second input signal, wherein the second input signal differs from the first input signal,

wherein the low-pass filters are allocated to the at least two partial ranges, each of the low-pass filters being configured to determine the number quantity allocated to its partial range.

10. The device according to claim 9, wherein the low-pass filter includes an exponential characteristic.

11. The device according to claim 9, wherein

as a result of triggering of the low-pass filter with the first input signal, the number quantity determined by this low-pass filter is incremented; and

as a result of the triggering of the low-pass filters with the second input signal, the number quantities determined by these low-pass filters is decremented.

12. The device according to claim 9, wherein a first average is determined by a first method from at least two successively determined values of the output signal of the vehicle sensor, and averages obtained by the first method are allocated to the partial ranges.

13. The device according to claim 9, wherein the vehicle sensor is configured to detect a yawing motion of the vehicle.

14. The device according to claim 13, the offset value is used to determine for at least one of automatic distance regulation and control adaptive cruise controlling the vehicle.

15. The device according to claim 9, wherein the offset value is determined by forming a weighted average in accordance with the partial range having a largest number of allocated values of the output signal and at least one adjacent interval.

16. The device according to claim 15, wherein weighting factors of the weighted average include one of linear values and quadratic values of the number quantities.