Method of detecting wear of a tyre

• US 8,892,298 B2
• Filed: 10/04/2012
• Issued: 11/18/2014
• Est. Priority Date: 10/06/2011
• Status: Active Grant

• Current Assignee: Compagnie Generale DES Etablissements Michelin SCA
• Original Assignee: Compagnie Generale DES Etablissements Michelin SCA, Michelin Recherche et Technique SA (Compagnie Generale DES Etablissements Michelin SCA)
• Inventors: Paturle, Antoine, Ducloux, Antoine
• Primary Examiner(s): FREJD, RUSSELL WARREN
• Application Number:
  US14/349,897
• Publication Number:
  US 20140277929A1
• Time in Patent Office: 775 Days
• Field of Search: 701/32.8, 701/32.9, 701/34.4, 152/154.2, 73/8, 731/46, 340/425.5, 340/438
• US Class Current: 701/34.4
• CPC Class Codes: B60C 11/03 Tread patterns
• CPC Class Codes: B60C 11/0318 irregular patterns with particular pitch sequence
• CPC Class Codes: B60C 11/24 Wear-indicating arrangements
• CPC Class Codes: B60C 11/243 Tread wear sensors, e.g. electronic sensors
• CPC Class Codes: B60C 11/246 Tread wear monitoring systems
• CPC Class Codes: B60C 2019/006 Warning devices, e.g. devices generating noise due to flat or worn tyres
• CPC Class Codes: B60C 2019/007 triggered by sensors
• CPC Class Codes: G01M 17/025 using infrasonic, sonic or ultrasonic vibrations
• CPC Class Codes: Y10T 152/10027 with wear indicating feature

Abstract

A method for detecting a wear condition of a tire utilizes tread pattern elements included on the tire. The elements are adapted to generate first and second acoustic footprint noises (BEA1, BEA2), with one of the first and second acoustic footprint noises being characteristic of the wear condition of the tire. According to the method, a parent frequency spectrum, which is capable of forming a frequency spectrum of one of the first and second acoustic footprint noises, and a child frequency spectrum, which is capable of forming a frequency spectrum of the other of the first and second acoustic footprint noises, are selected from a frequency spectrum of an acoustic signal acquired from the tire. Two detection confidence indices are determined. If each detection confidence index meets a predetermined condition, a warning is emitted indicating that tire wear has been detected.

Claims

1. A method for detecting a wear condition of a tyre that includes a first tread pattern element adapted to generate a first acoustic footprint noise and a second tread pattern element adapted to generate a second acoustic footprint noise, the first and second acoustic footprint noises being characteristic of the wear condition of the tyre, the method comprising steps of:

acquiring an acoustic signal that is capable of including the first and second acoustic footprint noises;

selecting a parent frequency spectrum, which is capable of forming a frequency spectrum of one of the first and second acoustic footprint noises, from within a frequency spectrum of the acquired acoustic signal;

determining a trimmed frequency spectrum by eliminating at least part of the parent frequency spectrum from the frequency spectrum of the acquired acoustic signal;

selecting a child frequency spectrum, which is capable of forming a frequency spectrum of another of the first and second acoustic footprint noises, from within the trimmed frequency spectrum;

determining two detection confidence indices, which are indices associated with detection of the first and second acoustic footprint noises, based on at least one characteristic of each of the parent frequency spectrum and the child frequency spectrum; and

if each of the two detection confidence indices meets a predetermined condition relating to detection of each of the first and second acoustic footprint noises, a warning is emitted indicating detection of wear of the tyre.

2. The method according to claim 1,

wherein the parent frequency spectrum includes elementary frequency components, and

wherein the method further comprises a step of retaining components of the elementary frequency components of the parent frequency spectrum having a spectral power density above a predetermined threshold.

3. The method according to claim 1, further comprising steps of:

listing at least one hypothetical frequency spectrum; and

determining at least one frequency characteristic of each hypothetical frequency spectrum.

4. The method according to claim 3, further comprising a step of, for each hypothetical frequency spectrum, determining a confidence or selection index, the confidence or selection index being associated with a selection of the hypothetical frequency spectrum.

5. The method according to claim 3,

wherein each hypothetical frequency spectrum includes elementary frequency components, and

wherein, for each hypothetical frequency spectrum, a frequency characteristic of the hypothetical frequency spectrum is a frequency difference separating each elementary frequency component, in frequency, from at least one adjacent elementary frequency component of the hypothetical spectrum.

6. The method according to claim 4,

wherein each hypothetical frequency spectrum includes elementary frequency components, and

wherein, for each hypothetical frequency spectrum, a frequency characteristic of the hypothetical frequency spectrum is a frequency difference separating each elementary frequency component, in frequency, from at least one adjacent elementary frequency component of the hypothetical spectrum.

7. The method according to claim 5, wherein the step of selecting the child frequency spectrum is limited to selecting from hypothetical frequency spectra whose frequency difference lies within a range of frequency differences determined based on a frequency difference of the parent frequency spectrum.

8. The method according to claim 6, wherein the step of selecting the child frequency spectrum is limited to selecting from hypothetical frequency spectra whose frequency difference lies within a range of frequency differences determined based on a frequency difference of the parent frequency spectrum.

9. The method according to claim 1, further comprising a step of selecting first and second potential frequency spectra within the frequency spectrum of the acquired acoustic signal, wherein each of the first and second potential frequency spectra is capable of forming a frequency spectrum of one of the first and second acoustic footprint noises, and wherein the parent frequency spectrum is selected from amongst the first and second potential frequency spectra.

10. The method according to claim 9, further comprising steps of:

listing at least one hypothetical frequency spectrum; and

determining at least one frequency characteristic of each hypothetical frequency spectrum,

wherein each hypothetical frequency spectrum includes elementary frequency components,

wherein, for each hypothetical frequency spectrum, a frequency characteristic of the hypothetical frequency spectrum is a frequency difference separating each elementary frequency component, in frequency, from at least one adjacent elementary frequency component of the hypothetical spectrum, and

wherein the first and second potential frequency spectra are selected from amongst hypothetical spectra having a frequency difference belonging, respectively, to first and second ranges of predetermined frequency differences.

11. A computer programmed with code that, when executed, performs method for detecting a wear condition of a tyre that includes a first tread pattern element adapted to generate a first acoustic footprint noise and a second tread pattern element adapted to generate a second acoustic footprint noise, the first and second acoustic footprint noises being characteristic of the wear condition of the tyre, the method comprising steps of:

acquiring an acoustic signal that is capable of including the first and second acoustic footprint noises;

selecting a parent frequency spectrum, which is capable of forming a frequency spectrum of one of the first and second acoustic footprint noises, from within a frequency spectrum of the acquired acoustic signal;

determining a trimmed frequency spectrum by eliminating at least part of the parent frequency spectrum from the frequency spectrum of the acquired acoustic signal;

selecting a child frequency spectrum, which is capable of forming a frequency spectrum of another of the first and second acoustic footprint noises, from within the trimmed frequency spectrum;

determining two detection confidence indices, which are indices associated with detection of the first and second acoustic footprint noises, based on at least one characteristic of each of the parent frequency spectrum and the child frequency spectrum; and

if each of the two detection confidence indices meets a predetermined condition relating to detection of each of the first and second acoustic footprint noises, a warning is emitted indicating detection of wear of the tyre.

12. A non-transitory computer-readable storage medium storing code that, when executed by a computer, causes the computer to perform a method for detecting a wear condition of a tyre that includes a first tread pattern element adapted to generate a first acoustic footprint noise and a second tread pattern element adapted to generate a second acoustic footprint noise, the first and second acoustic footprint noises being characteristic of the wear condition of the tyre, the method comprising steps of:

acquiring an acoustic signal that is capable of including the first and second acoustic footprint noises;

selecting a parent frequency spectrum, which is capable of forming a frequency spectrum of one of the first and second acoustic footprint noises, from within a frequency spectrum of the acquired acoustic signal;

determining a trimmed frequency spectrum by eliminating at least part of the parent frequency spectrum from the frequency spectrum of the acquired acoustic signal;

selecting a child frequency spectrum, which is capable of forming a frequency spectrum of another of the first and second acoustic footprint noises, from within the trimmed frequency spectrum;

determining two detection confidence indices, which are indices associated with detection of the first and second acoustic footprint noises, based on at least one characteristic of each of the parent frequency spectrum and the child frequency spectrum; and

if each of the two detection confidence indices meets a predetermined condition relating to detection of each of the first and second acoustic footprint noises, a warning is emitted indicating detection of wear of the tyre.

13. A process for detecting tyre wear, the processing comprising steps of:

storing, on a non-transitory computer-readable storage medium, code that when executed by a computer causes the computer to perform a method for detecting a wear condition of a tyre that includes a first tread pattern element adapted to generate a first acoustic footprint noise and a second tread pattern element adapted to generate a second acoustic footprint noise, the first and second acoustic footprint noises being characteristic of the wear condition of the tyre, the method including;

acquiring an acoustic signal that is capable of including the first and second acoustic footprint noises;

selecting a parent frequency spectrum, which is capable of forming a frequency spectrum of one of the first and second acoustic footprint noises, from within a frequency spectrum of the acquired acoustic signal;

determining a trimmed frequency spectrum by eliminating at least part of the parent frequency spectrum from the frequency spectrum of the acquired acoustic signal;

selecting a child frequency spectrum, which is capable of forming a frequency spectrum of another of the first and second acoustic footprint noises, from within the trimmed frequency spectrum;

determining two detection confidence indices, which are indices associated with detection of the first and second acoustic footprint noises, based on at least one characteristic of each of the parent frequency spectrum and the child frequency spectrum; and

if each of the two detection confidence indices meets a predetermined condition relating to detection of each of the first and second acoustic footprint noises, a warning is emitted indicating detection of wear of the tyre; and

enabling the code to be downloaded via a telecommunications network.