Method and line for checking tyres for vehicle wheels

Patent metadata

Field	Value
Publication number	US-10989628-B2
Application number	US-201716300464-A
Country	US
Kind code	B2
Filing date	May 17, 2017
Priority date	May 18, 2016
Publication date	Apr 27, 2021
Grant date	Apr 27, 2021

Abstract

A checking method and line for checking a tyre for vehicle wheels. The tyre is associated with a model associated with a setting for image acquisition devices. Once the model is obtained, preliminary images of the tyre are acquired, from which at least one adjustment value representative of at least one geometric characteristic of the tyre is obtained. A deviation between the at least one adjustment value and a respective reference value associated with the model is then calculated. The setting associated with the model of tyre is then adjusted based on the calculated deviation and the tyre is then inspected to look for possible production defects by acquiring images of at least part of the surface of the tyre using the image acquisition devices, set according to the adjusted setting.

First claim

The invention claimed is:

1. A method for checking a tyre for vehicle wheels, said tyre being associated with a model, the method comprising:
a) obtaining the model associated with said tyre, the model being associated with a setting for positioning a set of image acquisition devices;
b) acquiring preliminary images of said tyre;
c) obtaining, from said acquired preliminary images, at least one adjustment value representative of at least one geometric characteristic of the tyre;
d) calculating a deviation between said at least one adjustment value and a respective reference value, associated with said model;
e) adjusting the setting associated with the model of the tyre based on the calculated deviation; and
(f) inspecting said tyre to look for possible production defects by acquiring images of at least part of the surface of the tyre,
wherein inspecting said tyre includes using the set of image acquisition devices set according to the setting thus adjusted for acquiring the images of at least part of the surface of the tyre.

2. The method according to claim 1 , further comprising establishing whether said at least one geometric characteristic of the tyre is in compliance with reference specifications for said model.

3. The method according to claim 2 , wherein c), d) and e) are carried out if said at least one geometric characteristic is in compliance with said reference specifications.

4. The method according to claim 3 , wherein said reference specifications for said model comprise a first threshold and wherein the establishing whether said at least one geometric characteristic of the tyre is in compliance with said reference specifications comprises:
obtaining from said acquired preliminary images a control value relative to said at least one geometric characteristic of the tyre,
comparing said control value with said first threshold, and
establishing compliance of said at least one geometric characteristic when said control value is less than or equal to said first threshold and the non-compliance when said control value is greater than said first threshold.

5. The method according to claim 3 , wherein said reference specifications for said model comprise a first threshold and a second threshold, smaller than the first threshold, and wherein establishing whether said at least one geometric characteristic of the tyre is in compliance with said reference specifications comprises:
obtaining from said acquired preliminary images a control value relative to said at least one geometric characteristic of the tyre,
comparing said control value with said first threshold and said second threshold,
establishing the compliance of said at least one geometric characteristic when said control value is less than or equal to said first threshold and greater than or equal to said second threshold, and
establishing non-compliance of said at least one geometric characteristic when said control value is greater than said first threshold or less than said second threshold.

6. The method according to claim 5 , wherein, when said control value is greater than said first threshold, the tyre is discarded without carrying out c), d) and e).

7. The method according to claim 6 , wherein, when said control value is less than said second threshold, said tyre is inspected to look for possible production defects by acquiring images of at least part of the surface of the tyre, using the set of image acquisition devices set according to the setting associated with the model of the tyre, without carrying out c), d) and e).

8. The method according to claim 1 , further comprising obtaining from said preliminary images a profile of a portion of the tyre and in c) obtaining said at least one adjustment value from said profile.

9. The method according to claim 7 , further comprising obtaining from said preliminary images a profile of a portion of the tyre and obtaining said control value relative to said at least one geometric characteristic of the tyre from said profile.

10. The method according to claim 8 , wherein said respective reference value corresponds to said adjustment value in a reference profile, associated with said model of the tyre, corresponding to the obtained profile.

11. The method according to claim 10 , wherein said portion of the tyre from which the profile is obtained is an outer surface portion of the tyre.

12. The method according to claim 8 , wherein said portion of the tyre from which the profile is obtained is at least one outer side surface portion of the tyre.

13. The method according to claim 1 , wherein in b) said preliminary images are acquired at low resolution.

14. The method according to claim 1 , wherein said setting comprises a plurality of positions for said set of image acquisition devices that allow said set of image acquisition devices to acquire said images of said at least part of the surface of the tyre.

15. The method according to claim 14 , wherein in c) said at least one adjustment value is representative of said at least one geometric characteristic of the tyre at a respective position among said plurality of positions.

16. The method according to claim 15 , wherein said respective position among said plurality of positions allows said acquisition of images relative to at least one from: at least one outer side surface portion of the tyre and at least one inner side surface portion of the tyre.

17. The method according to claim 1 , wherein said at least one geometric characteristic of the tyre comprises at least one from: level of an outer side surface portion and level of an inner side surface portion of the tyre, wherein, in a radial section plane of the tyre that contains a rotation axis of the tyre, said level represents a distance, along a parallel to said rotation axis, between said outer or inner side surface portion and an axial middle plane of the tyre, perpendicular to the rotation axis of the tyre.

18. The method according to claim 1 , wherein in b) said preliminary images are acquired through preliminary image acquisition devices arranged according to predetermined positions.

19. The method according to claim 18 , wherein in b) the preliminary images of an outer surface portion of the tyre are acquired during a translation of the tyre, along an advancing direction, with respect to said preliminary image acquisition devices that remain stationary in the respective predetermined positions, said advancing direction being perpendicular to the rotation axis of the tyre.

20. The method according to claim 19 , wherein said acquisition of preliminary images of the outer surface portion of the tyre comprises formation of two slit lights on a plane substantially perpendicular to said advancing direction, adapted to illuminate as a whole said outer surface portion of the tyre while the tyre translates along said advancing direction.

21. The method according to claim 1 further comprising obtaining a variation of the deviation calculated in d) for different tyres associated with said model.

22. The method according to claim 21 , wherein, if the obtained variation satisfies predetermined conditions, the setting associated with the model of the tyre is replaced with a setting adjusted based on the variation obtained.

23. A checking line of a tyre for vehicle wheels, said tyre being associated with a model, the checking line comprising:
a plurality of checking stations comprising a set of image acquisition devices and preliminary image acqu

Assignees

• Pirelli

Inventors

• Boffa Vincenzo
• Cantù Marco
• Regoli Fabio
• Ballardini Valeriano

Classifications

• H04N23/56

  provided with illuminating means · CPC title

• H04N23/90

  Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums · CPC title

• G01M11/081

  by using a contact-less detection method, i.e. with a camera · CPC title

• G01B11/2522

  the position of the object changing and being recorded · CPC title

• G01B11/245

  using a plurality of fixed, simultaneously operating transducers ({G01B11/2408 - G01B11/2425, } G01B11/255 take precedence) · CPC title