Method for determining a tread depth of a tire profile and control device therefor

Patent metadata

Field	Value
Publication number	US-10495457-B2
Application number	US-201815905541-A
Country	US
Kind code	B2
Filing date	Feb 26, 2018
Priority date	Aug 25, 2015
Publication date	Dec 3, 2019
Grant date	Dec 3, 2019

Abstract

A method is for determining a profile depth of a tire profile. The method includes at least the following steps: a) detecting an acceleration of a measurement point on a tire inner side of a vehicle tire, wherein a deviation, caused by contact of the vehicle tire with a roadway, of the acceleration of the measurement point within an observation window is detected, b) deriving at least one analytical characteristic variable which is characteristic of the profile of the detected acceleration, wherein the at least one analytical characteristic variable characterizes the non-periodic profile of the detected acceleration within one tire rotation, c) determining the profile depth in a manner dependent on the at least one analytical characteristic variable, wherein a calibration curve yields the dependency between the analytical characteristic variable and the profile depth, and the calibration curve assigns a profile depth to the derived analytical characteristic variable.

First claim

What is claimed is:

1. A method for determining a profile depth of a tire profile, the method comprising the steps of:
a) detecting an acceleration of a measurement point on a tire inner side of a vehicle tire, wherein a deviation, caused by contact of the vehicle tire with a roadway, of the acceleration of the measurement point within an observation window is detected;
b) deriving at least one analytical characteristic variable which is characteristic of the profile of the detected acceleration, wherein the at least one analytical characteristic variable characterizes a non-periodic profile of the detected acceleration within one tire rotation; and,
c) determining the profile depth in a manner dependent on the at least one analytical characteristic variable, wherein a calibration curve yields the dependency between the analytical characteristic variable and the profile depth and the calibration curve assigns a profile depth to the derived analytical characteristic variable.

2. The method of claim 1 , wherein the determination of the profile depth includes using a calibration curve which maps the analytical characteristic variable onto the profile depth such that each value of the at least one analytical characteristic variable is assigned exactly one value of the profile depth.

3. The method of claim 1 , wherein:
the determination of the profile depth includes using a calibration curve which runs within a linear tolerance band; and,
the tolerance band runs with a deviation of less than 15% around a linear approximation to the calibration curve.

4. The method of claim 1 , wherein:
the determination of the profile depth includes using a calibration curve which runs within a linear tolerance band; and,
the tolerance band runs with a deviation of less than 5% around a linear approximation to the calibration curve.

5. The method of claim 1 , wherein the determination of the profile depth includes using a calibration curve which runs linearly and the profile depth is determined from a multiplication of the at least one analytical characteristic variable by a gradient of the calibration curve taking into consideration a tire characteristic constant.

6. The method of claim 1 , wherein each analytical characteristic variable is assigned in each case one calibration curve.

7. The method of claim 1 , wherein at least one analytical characteristic variable is derived from a change in a radial acceleration versus a time or a traversed rolling circumference or a traversed angle of the measurement point on the vehicle tire.

8. The method of claim 7 , wherein a maximum negative change within a tire contact patch region or a maximum positive change within the tire contact patch region of the radial acceleration versus the time or the traversed rolling circumference or the traversed angle of the measurement point on the vehicle tire is derived as at least one analytical characteristic variable.

9. The method of claim 7 , wherein a weighted average value of a maximum negative change within a tire contact patch region and a maximum positive change within a tire contact patch region of the radial acceleration versus the time or the traversed rolling circumference or the traversed angle of the measurement point on the vehicle tire is derived as at least one analytical characteristic variable.

10. The method of claim 7 , wherein the derivation of the at least one analytical characteristic variable from the change of the radial acceleration includes:
forming a characteristic curve from the detected radial acceleration;
selecting at least one observation point on the characteristic curve; and,
deriving the change of the radial acceleration from the at least one observation point.

11. The method of claim 10 , wherein the derivation of the change of the radial acceleration includes forming a derivative of the characteristic curve formed by the radial acceleration versus the time or the traversed rolling circumference or the traversed angle of the measurement point on the vehicle tire.

12. The method of claim 1 , wherein the at least one analytical characteristic variable is derived from a tangential acceleration at the measurement point.

13. The method of claim 12 , wherein a maximum tangential acceleration within a tire contact patch region or a minimum tangential acceleration within the tire contact patch region is derived as at least one analytical characteristic variable, wherein the maximum and the minimum tangential acceleration are determined from at least one of a profile of the detected tangential acceleration averaged in weighted fashion over multiple tire rotations and a profile of the detected tangential acceleration smoothed in accordance with the floating mean value principle.

14. The method of claim 12 , wherein a weighted average value of a maximum tangential acceleration within the tire contact patch region and a minimum tangential acceleration within the tire contact patch region is derived as at least one analytical characteristic variable.

15. The method of claim 12 , wherein the derivation of the at least one analytical characteristic variable from the tangential acceleration includes:
forming a characteristic curve versus the time or a traversed rolling circumference or a traversed angle of the measurement point on the vehicle tire from the detected tangential acceleration;
selecting at least one observation point on the characteristic curve; and,
determining the tangential acceleration from an ordinate value of the at least one observation point.

16. The method of claim 1 , wherein:
a time interval or an angular interval or a distance difference along the rolling circumference between two acceleration states of the measurement point is derived from the detected acceleration as at least one analytical characteristic variable;
the detected acceleration in both acceleration states is approximately identical;
the detected acceleration in both acceleration states corresponds to a value which is less than 25% or more than 75% of a maximum detected acceleration within a tire contact patch region; and,
the maximum detected acceleration is determined from at least one of a profile of the detected acceleration averaged in weighted fashion over multiple tire rotations and a profile of the detected acceleration smoothed in accordance with the floating mean value principle.

17. The method of claim 1 , wherein:
a time interval or an angular interval or a distance difference along the rolling circumference between two acceleration states of the measurement point is derived from the detected acceleration as at least one analytical characteristic variable;
the detected acceleration in both acceleration states is approximately identical;
the detected acceleration in both acceleration states corresponds to a value which is less than 5% or 100% of a maximum detected acceleration within a tire contact patch region; and,
the maximum detected acceleration is determined from at least one of a profile of the detected acceleration averaged in weighted fashion over multiple tire rotations and a profile of the detected acceleration smoothed in accordance with the floating mean value principle.

18. The method of claim 16 , wherein the derivation of the at least one analytical characteristic variable from the time interval or the angular interval or the distance difference along the rolling circumference includes:
forming a characteristic curve versus the time or the traversed rolling circumference or the traversed angle of the measurement point on the vehicle tire fr

Assignees

• Continental Reifen Deutschland Gmbh

Inventors

• Cyllik Adrian
• Hahn Carsten
• Lehn Michael
• Volk Heiner
• Welser Joachim
• Neuber Cord-Christian
• Huynh Jenny

Classifications

• B60C2019/004

  Tyre sensors other than for detecting tyre pressure · CPC title

• B60C11/246 Primary

  Tread wear monitoring systems · CPC title

• G01B21/20

  for measuring contours or curvatures, e.g. determining profile · CPC title

• G01B21/18 Primary

  for measuring depth · CPC title

• G01M17/02

  Tyres · CPC title