System and method for analyzing tire tread parameters

Patent metadata

Field	Value
Publication number	US-10507700-B2
Application number	US-201314893748-A
Country	US
Kind code	B2
Filing date	Jul 31, 2013
Priority date	Jul 31, 2013
Publication date	Dec 17, 2019
Grant date	Dec 17, 2019

Abstract

Systems and methods for analyzing tread surface data to assess tire tread parameters, such as irregular wear characteristics of a tire tread, are provided. For example, tread surface data, such as a tread surface map, can be processed to generate a convex hull for the tire. The convex hull can approximate the convex outer surface of the tire. The convex hull can be used as a reference for analyzing the tread surface data. In particular, irregular wear zones in the tire tread can be mathematically concave relative to the convex hull. Comparing the tread surface data to the convex hull can reveal information indicative of irregular wear characteristics of the tire. For instance, the local depth of the measured tread surface data relative to the convex hull can provide a quantitative measure of irregular wear characteristics of the tire.

First claim

What is claimed is:

1. A method for assessing one or more parameters of a tread of a tire, comprising:
obtaining a tread surface map for the tread of the tire using a laser probe adapted to measure the tread of the tire, the tread surface map comprising a plurality of data points, each data point providing a tread height for the tread of the tire;
processing, with one or more computing devices, the tread surface map to generate a convex hull, the convex hull comprising a three-dimensional shell that wraps the tread surface map, the convex hull being convex at all points around the convex hull;
determining, with the one or more computing devices, a relative tread depth map based at least in part on the tread surface map and the convex hull, the relative tread depth map being determined as the difference between the convex hull and the tread surface map; and
analyzing, with the one or more computing devices, the relative tread depth map to assess one or more parameters of the tread of the tire;
wherein processing the tread surface map to generate a convex hull comprises performing a Delaunay triangulation process on the tread surface map, wherein the Delaunay triangulation process models the convex hull as a plurality of Delaunay triangles.

2. The method of claim 1 , wherein the method comprises filtering the tread surface map.

3. The method of claim 1 , wherein the method comprises modifying the tread surface map prior to processing the tread surface map to generate the convex hull.

4. The method of claim 3 , wherein modifying the tread surface map prior to processing the tread surface map to generate a convex hull comprises extending the tread surface map in the circumferential direction.

5. The method of claim 3 , wherein modifying the tread surface map prior to processing the tread surface map to generate a convex hull comprises:
determining a profile of the tread surface map;
detecting a first limit of the profile of the tread surface map by comparing the slope of the profile to a threshold slope;
detecting a second limit of the profile of the tread surface map by comparing the slope of the average profile to the threshold slope;
modifying a first point on the tread surface map by performing a linear extrapolation of a straight line that starts at the first limit and has a slope equal to the threshold slope; and
modifying a second point on the tread surface map by performing a linear extrapolation of a straight line that starts at the second limit and has a slope equal to the threshold slope.

6. The method of claim 5 , wherein modifying the first point on the tread surface map and modifying the second point on the tread surface map comprises implementing a local maximum filter.

7. The method of claim 3 , wherein modifying the tread surface map prior to processing the tread surface map to generate a convex hull comprises:
determining a bending curve having a maximum at the center of a profile of the tread surface map; and
modifying the tread surface map by determining the difference between the tread surface map and the bending curve.

8. The method of claim 3 , wherein modifying the tread surface map prior to processing the tread surface map to generate a convex hull comprises compacting the tread surface map to extend along a fraction of a circumference of the tread.

9. The method of claim 1 , wherein the tread surface map is generated from a laser probe, sonic probe, optical probe, or video probe.

10. The method of claim 1 , wherein the one or more parameters of the tread of the tire comprise irregular wear characteristics of the tread of the tire.

11. The method of claim 1 , wherein the one or more parameters of the tread of the tire comprise a groove depth of the tread of the tire.

12. A system for assessing one or more parameters of a tread of a tire, the system comprising:
a laser probe adapted to measure a tread surface map of the tread of the tire, the tread surface map comprising a plurality of data points, each data point providing a tread height for the tread of the tire;
a computing system having one or more processors and one or more computer-readable media, the one or more processors configured to execute computer-readable instructions stored in the one or more computer-readable media to cause the one or more processors to perform operations, the operations comprising:
processing the tread surface map to generate a convex hull, the convex hull comprising a three-dimensional shell that wraps the tread surface map, the convex hull being convex at all points around the convex hull;
determining a relative tread depth map based at least in part on the tread surface map and the convex hull, the relative tread depth map being determined as the difference between the convex hull and the tread surface map; and
analyzing the relative tread depth map to assess one or more parameters of the tread of the tire;
wherein the operation of processing the tread surface map to generate a convex hull comprises performing a Delaunay triangulation process on the tread surface map, the Delaunay triangulation process modeling the convex hull as a plurality of Delaunay triangles.

13. The system of claim 12 , wherein the operations further comprise modifying the tread surface map prior to processing the tread surface map to generate the convex hull.

14. The system of claim 13 , wherein the operation of modifying the tread surface map prior to processing the tread surface map to generate the convex hull comprises:
determining a profile of the tread surface map;
detecting a first limit of the profile of the tread surface map by comparing the slope of the profile to a threshold slope;
detecting a second limit of the profile of the tread surface map by comparing the slope of the average profile to the threshold slope;
modifying a first point on the tread surface map by performing a linear extrapolation of a straight line that starts at the first limit and has a slope equal to the threshold slope; and
modifying a second point on the tread surface map by performing a linear extrapolation of a straight line that starts at the second limit and has a slope equal to the threshold slope.

15. The system of claim 13 , wherein the operation of modifying the tread surface map prior to processing the tread surface map to generate the convex hull comprises:
determining a bending curve having a maximum at the center of a profile of the tread surface map; and
modifying the tread surface map by determining the difference between the tread surface map and the bending curve.

16. The system of claim 13 , wherein the operation of modifying the tread surface map prior to processing the tread surface map to generate the convex hull comprises compacting the tread surface map to extend along a fraction of a circumference of the tread.

Assignees

• Michelin & Cie
• Michelin Rech Tech

Inventors

• Neau Xavier

Classifications

• B60C11/246

  Tread wear monitoring systems · CPC title

• G01B11/22

  for measuring depth · CPC title

• G01M17/027

  using light, e.g. infrared, ultraviolet or holographic techniques · CPC title

• G06T17/20

  Finite element generation, e.g. wire-frame surface description, {tesselation} · CPC title

• G01B11/24

  for measuring contours or curvatures · CPC title