Tire uniformity improvement through identification of measurement process harmonics using Weibull regression

Patent metadata

Field	Value
Publication number	US-10416044-B2
Application number	US-201415500185-A
Country	US
Kind code	B2
Filing date	Jul 31, 2014
Priority date	Jul 31, 2014
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

Methods and systems for improving the uniformity of a tire are provided. More particularly, a magnitude of a uniformity parameter can be obtained for each tire in a set of a plurality of tires. The magnitudes associated with the set of tires can be transformed according to a probability distribution function (e.g. a Weibull distribution function) to obtain a set of transformed magnitudes. Parameters associated with a probability distribution function can be estimated based at least in part on the transformed magnitudes. Parameters associated with the probability distribution function can be used to determine data indicative of a measurement error in the uniformity measurements attributable to a measurement process harmonic. The data indicative of the measurement error can be used to correct uniformity measurements obtained for tires and to modify tire manufacture based at least in part on the corrected measurements.

First claim

What is claimed is:

1. A method of improving the uniformity of a tire, comprising:
obtaining, by one or more computing devices, a set of magnitudes of a uniformity parameter measured for a set of a plurality of tires, each magnitude being associated with one of the tires in the set of the plurality of tires;
transforming, by the one or more computing devices; the set of magnitudes to generate a set of transformed magnitudes, the transformed magnitudes associated with a generally linear distribution;
estimating, by the one or more computing devices, one or more parameters of a probability distribution from the transformed magnitudes based on one or more parameters associated with the generally linear distribution;
determining, by the one or more computing devices, data indicative of a measurement error attributable to a measurement process harmonic based at least in part on the one or more parameters of the probability distribution; and
modifying tire manufacture based at least in part on the data indicative of the measurement error.

2. The method of claim 1 , wherein the probability distribution is a Weibull distribution.

3. The method of claim 1 , wherein transforming, by the one or more computing devices, the set of magnitudes to generate a set of transformed magnitudes, comprises:
determining a sort order for the set of magnitudes;
assigning each magnitude in the set of magnitudes a quantile based at least in part on the sort order for the set of magnitudes;
transforming the quantile for each magnitude in the set of magnitudes in accordance with the probability distribution to generate a transformed quantile;
transforming each magnitude in the set of magnitudes to generate a transformed magnitude for each transformed quantile;
determining a transformed sort order based at least in part on the transformed quantile for each transformed magnitude.

4. The method of claim 3 , wherein the quantile for each magnitude is transformed in accordance with the probability distribution as follows:
q t =log(log(1/(1−/ q )))

where q t is the transformed quantile and q is the quantile; and
each transformed magnitude is obtained from each magnitude as follows:
m t =log m

where m t is the transformed magnitude and m is the magnitude.

5. The method of claim 1 , wherein estimating, by the one or more computing devices, one or more parameters of a probability distribution comprises:
estimating a slope and an intercept of a best fitting line to the generally linear distribution; and
determining the one or more parameters of a Weibull distribution based at least in part on the slope and the intercept.

6. The method of claim 5 , wherein the one or more parameters of the Weibull distribution comprise a shape parameter and a scale parameter of the Weibull distribution.

7. The method of claim 6 , wherein the shape parameter is estimated based at least in part on the slope of the best fitting line and the scale parameter is estimated based at least in part on the intercept of the best fitting line.

8. The method of claim 7 , wherein the data indicative of the measurement error comprises a variance attributable to the measurement process harmonic.

9. The method of claim 7 , wherein the variance attributable to the measurement process harmonic is estimated based at least in part on the shape parameter of the Weibull distribution.

10. The method of claim 1 , wherein modifying tire manufacture based at least in part on the data indicative of the measurement error comprises correcting uniformity measurements for one or more tires based at least in part on the data indicative of the measurement error to determine corrected uniformity measurements for the one or more tires.

11. The method of claim 10 , wherein modifying tire manufacture comprises sorting or grading the one or more tires based at least in part on the corrected uniformity measurements.

12. The method of claim 10 , wherein modifying tire manufacture comprises analyzing the corrected uniformity measurements of the one or more tires to identify one or more process harmonics or tire harmonics.

13. The method of claim 1 , wherein the uniformity parameter comprises one or more of low and high speed radial force variation, tangential force variation, radial run out, lateral run out, mass variance, conicity, ply steer, and one or more harmonics thereof.

14. A system for improving the uniformity of tires, comprising:
a uniformity measurement machine configured to obtain uniformity measurements of a uniformity parameter for a set of a plurality tires;
one or more computing devices in communication with the uniformity measurement machine, the one or more computing devices comprising computer-readable instructions stored in one or more memory devices that when executed by one or more processors, cause the one or more processors to operations, the operations comprising:
obtaining a set of magnitudes of a uniformity parameter measured for a set of a plurality of tires, each magnitude being associated with one of the tires in the set of the plurality of tires;
transforming the set of magnitudes to generate a set of transformed magnitudes, wherein the set of magnitudes are associated with a generally linear distribution;
estimating one or more parameters of a probability distribution from the transformed magnitudes;
determining data indicative of a measurement error attributable to a measurement process harmonic based at least in part on the one or more parameters of the probability distribution.

Assignees

• Michelin & Cie
• Michelin Rech Tech
• Mawby William David

Inventors

• Mawby William David

Classifications

• B29D2030/0635

  Measuring and calculating tyre uniformity, e.g. using mathematical methods · CPC title

• G01M17/02 Primary

  Tyres · CPC title

• B29D30/0061

  Accessories, details or auxiliary operations not otherwise provided for · CPC title

• B29D2030/0066

  Tyre quality control during manufacturing · CPC title