Method for ascertaining a rotational direction of a rotating body, and wheel sensor module

• US 20110082663A1
• Filed: 09/29/2010
• Published: 04/07/2011
• Est. Priority Date: 10/02/2009
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Brockmann, Markus, Geisler, Dominik, Wenzler, Axel
• Granted Patent: US 8,751,190 B2
• Time in Patent Office: Days
• US Class Current: 702/141
• CPC Class Codes: B60C 23/0416 allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
• CPC Class Codes: G01P 13/04 Indicating positive or negative direction of a linear movement or clockwise or anti-clockwise direction of a rotational movement
• CPC Class Codes: G01P 3/22 transferred to the indicator by electric or magnetic means

Abstract

In a method for ascertaining a rotational direction of a rotating body, one rotational direction and one rotational speed value which indicates the rotational frequency of the rotating body are ascertained in each of multiple measurements. The rotational speed values of the multiple measurements are compared to each other, and a rotational direction of the rotating body is ascertained from the measured rotational directions and the comparison of the rotational speed values.

Claims

1. A method for ascertaining a rotational direction of a rotating body, comprising:

measuring, in each of multiple measurements, one rotational direction and one rotational speed value indicating the rotational frequency of the rotating body;

comparing the rotational speed values of the multiple measurements to each other; and

ascertaining the rotational direction of the rotating body based on the measured rotational directions and the comparison of the rotational speed values.

2. The method as recited in claim 1, wherein in each of the measurements, at least two acceleration sensors each measure a gravitational acceleration with a phase shift, and the rotational speed value and the rotational direction are ascertained from the values measured by the two acceleration sensors.

3. The method as recited in claim 2, further comprising:

comparing the measured rotational directions to each other; and

ascertaining an overall rotational speed value of the rotating body based on the comparison of the rotational speed values of the multiple measurements.

4. The method as recited in claim 2, wherein for multiple measurements recorded within a specified time period, intervals of the rotational speed values relative to each other are evaluated, and the rotational direction of the rotating body is ascertained based on the evaluation.

5. The method as recited in claim 4, wherein in the evaluation of the intervals of the rotational speed values relative to each other, a most significant rotational speed value is ascertained, and the rotational direction assigned to the most significant rotational speed value is determined as the rotational direction of the rotating body.

6. The method as recited in claim 5, wherein the ascertainment of the most significant rotational speed value is carried out using a rating function which assigns rating values to the intervals.

7. The method as recited in claim 6, wherein the rating function assigns rating values to each of the intervals of the rotational speed values, and for each ascertained rotational speed value a sum of the rating values of the intervals is formed, and based on the sum the most significant rotational speed value is ascertained.

8. The method as recited in claim 7, wherein the rating values are allocated to the intervals as a function of the size of the intervals.

9. The method as recited in claim 7, wherein a frequency range within which the rotational speed values of the ascertained measurements lie is subdivided into discretized rotational speed values, and the discretized rotational speed values are assessed as a function of distance from the ascertained rotational speed values of the measurements.

10. The method as recited in claim 2, wherein, for a first set of measurements, a centrifugal acceleration is ascertained from the values measured by the two acceleration sensors, and wherein a relationship between the ascertained centrifugal acceleration and rotational speed values is ascertained from the first set of measurements, and wherein subsequent measurements are compared to the ascertained relationship to determine whether the subsequent measurements are erroneous.

11. The method as recited in claim 10, wherein a proportionality factor is ascertained from the centrifugal acceleration and rotational speed values of the first set of measurements, and wherein the proportionality factor is used to determine whether the subsequent measurements are erroneous.

12. A non-transitory computer-readable storage medium storing a computer program having codes which, when executed on a computer, perform a method for ascertaining a rotational direction of a rotating body, the method comprising:

measuring, in each of multiple measurements, one rotational direction and one rotational speed value indicating the rotational frequency of the rotating body;

comparing the rotational speed values of the multiple measurements to each other; and

ascertaining the rotational direction of the rotating body based on the measured rotational directions and the comparison of the rotational speed values.

13. A wheel sensor module for a vehicle wheel, comprising:

two acceleration sensor devices configured to measure two accelerations at least one of (a) in different directions and (b) in different places on the vehicle wheel, wherein the two acceleration sensor devices are configured to perform multiple measurements and output measured acceleration values for the multiple measurements; and

a control device configured to receive the measured acceleration values for the multiple measurements and ascertain rotational speed values and rotational directions of the vehicle wheel, wherein the control device is configured to compare the ascertained rotational speed values and the ascertained rotational directions of the multiple measurements to each other, and wherein the control device is configured to ascertain an overall rotational direction of the vehicle wheel as a function of the comparison.

14. The wheel sensor module as recited in claim 13, wherein the acceleration sensor devices are configured to:

measure a tangential acceleration and a radial acceleration;

calculate a centrifugal acceleration from the ascertained radial acceleration; and

ascertains the overall rotational direction of the vehicle wheel based on the accelerations.