Method for detecting and estimating an angle of rotation on itself of a wheel unit with an integrated radial acceleration sensor

Patent metadata

Field	Value
Publication number	US-10960713-B2
Application number	US-201716310073-A
Country	US
Kind code	B2
Filing date	Jun 16, 2017
Priority date	Jun 17, 2016
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

Abstract

A method for detecting and estimating an angle of rotation on itself, about a mounting axis, of a wheel unit with an acceleration sensor, the wheel unit being associated with a tire mounted on a rim, forming a wheel, the sensor detecting a gravitational force during the rotation of the wheel, forming a sinusoid. The wheel unit is mounted on the wheel with the acceleration sensor directly or indirectly inclined with respect to a plane tangential to the rim. The angle of rotation on itself of said wheel unit and therefore of the acceleration sensor at a given instant is estimated by comparing at least one parameter of the sinusoids that are obtained for the wheel unit in an initial mounting position on the wheel and in its position at this given instant, respectively.

First claim

The invention claimed is:

1. A method for detecting and estimating an angle of rotation on itself, about a mounting axis, of a wheel unit for measuring operating parameters of a tire with a radial acceleration sensor integrated into said wheel unit, the tire being mounted on a rim, forming, with the rim, a vehicle wheel able to rotate about a rolling axis, the sensor detecting a gravitational force during the rotation of the wheel forming a sinusoid as a function of time, the rotational speed of the wheel being a function of the diameter of the wheel and of the period of the sinusoid, wherein the wheel unit is mounted on the wheel with the acceleration sensor directly or indirectly inclined with respect to a plane tangential to the rim, and wherein the angle of rotation on itself of said wheel unit and therefore of said acceleration sensor at a given instant is estimated by comparing at least one parameter of the sinusoids that are obtained for the wheel unit in an initial mounting position on the wheel and in its position at this given instant, respectively.

2. The detection and estimation method as claimed in claim 1 , wherein said at least one parameter of the sinusoids for estimating the angle of rotation on itself of said wheel unit is a difference in amplitude of the sinusoids or a phase offset between the sinusoids in the initial mounting position of the wheel unit and at the given instant.

3. The detection and estimation method as claimed in claim 2 , wherein said at least one parameter of the sinusoids for estimating the angle of rotation on itself of said wheel unit is a difference in amplitude of the sinusoids and a phase offset between the sinusoids in the initial position and at a given instant.

4. The detection and estimation method as claimed in claim 3 , wherein, when said at least one parameter is at least one difference in amplitude of the sinusoids, there is estimation of a maximum amplitude Gr at an angle of rotation φ on itself of said wheel unit as a function of a nominal maximum amplitude Grnom in the initial position, using the following formula:
Gr=Gr nom·cos(φ/2) for φ between [0 and 90°] and [180° and 270°]

Gr=Gr nom·sin(φ/2) for φ between [90 and 180°] and [270° and 360°].

5. The detection and estimation method as claimed in claim 3 , wherein, when said at least one parameter is at least one phase offset of the sinusoids, the acceleration sensor transmitting radio waves toward the outside of the wheel unit at a predetermined angle of rotation of the wheel for the transmission, the actual angle of rotation of the wheel at the instant of the transmission moreover being measured, if this predetermined angle of rotation for the transmission does not correspond to the actual angle of rotation of the wheel at the instant of the transmission, there is deduced from this a rotation on itself of the wheel unit by an angle that is the difference between the predetermined angle of rotation for the transmission and the actual angle of rotation of the wheel at the instant of the transmission.

6. The detection and estimation method as claimed in claim 2 , wherein, when said at least one parameter is at least one difference in amplitude of the sinusoids, there is estimation of a maximum amplitude Gr at an angle of rotation p on itself of said wheel unit as a function of a nominal maximum amplitude Grnom in the initial position, using the following formula:
Gr=Gr nom·cos(φ/2) for φ between [0 and 90°] and [180° and 270°]

Gr=Gr nom·sin(φ/2) for φ between [90 and 180°] and [270° and 360°].

7. The detection and estimation method as claimed in claim 2 , wherein, when said at least one parameter is at least one phase offset of the sinusoids, the acceleration sensor transmitting radio waves toward the outside of the wheel unit at a predetermined angle of rotation of the wheel for the transmission, the actual angle of rotation of the wheel at the instant of the transmission moreover being measured, if this predetermined angle of rotation for the transmission does not correspond to the actual angle of rotation of the wheel at the instant of the transmission, there is deduced from this a rotation on itself of the wheel unit by an angle that is the difference between the predetermined angle of rotation for the transmission and the actual angle of rotation of the wheel at the instant of the transmission.

8. A method for monitoring and compensating a transmission power of radio waves from an acceleration sensor of a wheel unit, wherein there is estimation of an angle of rotation on itself of the wheel unit in accordance with a detection and estimation method as claimed in any one of the preceding claims and a range of firing angles considered to allow a transmission of radio waves with an acceptable power and, when this angle of rotation corresponds to a firing angle that is not within the predetermined range of firing angles, a diagnosis of unacceptable transmission power is transmitted.

9. The method as claimed in claim 8 , wherein there is compensation of the radio wave transmission power as a function of a predetermined table that is specific for each type of wheel unit.

10. A wheel unit for measuring operating parameters of a tire, said tire being mounted on a rim, the tire and the rim forming a vehicle wheel able to rotate about a rolling axis, the wheel unit comprising a support designed to be mounted on the wheel and bearing a radial acceleration sensor able to measure radial accelerations of the wheel, the radial acceleration sensor including a device for transmitting radio waves toward the outside of the wheel unit, wherein the radial acceleration sensor is mounted directly or indirectly inclined within an angular range with respect to a plane tangential to the rim and in that the unit comprises elements for comparing at least one parameter of the sinusoids that are obtained for a wheel unit in an initial mounting position on the wheel and in a position at a given instant, respectively, and elements for estimating an angle of rotation on itself of the wheel unit in order to implement a detection and estimation method as claimed in claim 1 .

11. The wheel unit as claimed in claim 10 , further comprising elements for computing a difference between the amplitudes of the sinusoids in the initial position and at a given instant and means for diagnosing an unacceptable modification of the transmission power of the transmission device of the wheel unit when the difference between the amplitudes is not within a predetermined range of firing angles stored in the wheel unit.

12. An assembly of a wheel central control unit, of a wheel anti-lock system and of wheels of a motor vehicle, each wheel comprising a wheel unit as claimed in claim 11 , the wheel anti-lock system comprising an angle coder able to measure the actual rotation of each wheel at a given instant and means for transmitting the measurements of the actual rotation of each wheel to the wheel central control unit, the transmission device of the wheel unit of each wheel transmitting radio waves to the wheel central control unit at a transmission angle of rotation of the wheel stored in the wheel central control unit, wherein the wheel central control unit has firstly elements for comparing the measurement of actual rotation of each wheel at the instant of transmission detected by the angle coder and the stored transmission angle of rotation, and secondly means for diagnosing when the difference between the measurement of actual rotation at the instant of transmission and the stored transmission angle of rotation is not within a predetermined range of firing angles stored in the wheel central control unit.

Assignees

• Continental Automotive France
• Continental Automotive Gmbh

Inventors

• Billy Stéphane
• Bouthinon Jean-Christophe

Classifications

• B60B37/10

  the wheels being individually rotatable around the axles · CPC title

• B60C23/0488 Primary

  Movement sensor, e.g. for sensing angular speed, acceleration or centripetal force · CPC title

• G01P3/44

  for measuring angular speed (G01P3/56 takes precedence) · CPC title