Apparatus and method for tire condition assessment

• US 6,069,966 A
• Filed: 07/03/1997
• Issued: 05/30/2000
• Est. Priority Date: 07/04/1996
• Status: Expired due to Fees

• Current Assignee: Snap-on Equipment Ltd. (Snap-On Incorporated)
• Original Assignee: Snap-on Equipment Ltd. (Snap-On Incorporated)
• Inventors: Davis, Stephen J., Stollery, David, Hawkins, Marcus J., Jones, Barbara L.
• Primary Examiner(s): Boudreau, Leo H.
• Assistant Examiner(s): CAGE, SHAWN B
• Application Number:
  US08/888,213
• Time in Patent Office: 1,062 Days
• Field of Search: 356/139.09, 73/146
• US Class Current: 382/100
• CPC Class Codes: G01B 11/22 for measuring depth

Abstract

Method and apparatus for automotive tire condition and other article assessment is based upon radiation analysis of a rotated tire. Analysis of reflected radiation on the basis of intensity sensing provides a measure of tread depth and sidewall profile, together with tread location and other data. By positional analysis of the tread depth locations there is provided complementary information on the tread wear pattern. Sidewall profile determination enables identification of other tire condition factors. Tread depth and sidewall profile are also determined by laser or other radiation line image displacement techniques and a mounting system is provided for the apparatus enabling determinations to be made without the use of a roller bed. Proper positional alignment of the wheel to the apparatus is determined by means of a reference datum derived from reflected radiation within the apparatus. Proper defined proximity of the tire is defined by a pair of alignment bars positioned over an optical window of the apparatus.

Claims

1. A method of tire condition assessment comprising the steps of

(a) mounting a tire to be tested for rotation including mounting a single radiation source and a radiation detector adjacent the tire by supporting the radiation source and the radiation detector from a vehicle on which the tire is mounted a vehicle on which the tire is mounted;

(b) directing incident radiation onto two or more circumferentially spaced locations on the tire by directing the radiation from only the single source of radiation as a band or stripe or line across at least a portion of the lateral width of the tire and locating the single source and the tire to be tested for illuminating the circumferentially spaced locations on the tire so that at each such location on the tire the incident direction is inclined to the tire radius at substantially the same oblique or non-zero angle;

(c) detecting radiation reflected from each of the locations on the tire by receiving at the detector radiation from at least said portion of the lateral width of the tire;

(d) processing the detected radiation to provide a radiation analysis function including information relative to a profile of the tire; and

(e) determining at least one characteristic of the condition of the tire by reference to its profile including obtaining a measure of tread depth at each of said circumferentially-spaced locations on the tire on the basis of image displacement or offset by the tread depth;

the processing and determining steps being carried out during movement of the vehicle or after such movement.

2. A method according to claim 1, further comprising the step of performing an image analysis function in relation to the reflected radiation.

3. A method according to claim 1, further comprising the step of effecting an intensity analysis function in relation to the reflected radiation.

4. A method according to claim 1, wherein the radiation is laser radiation, and the radiation analysis function includes the step of effecting an image displacement analysis function in relation to the reflected radiation.

5. A method of making diagnostic and/or maintenance determinations of tire or wheel data on an automotive vehicle wheel without removing same from the vehicle, the method comprising the step of:

(a) removably mounting a radiation source and a radiation detector adjacent to the wheel by supporting the radiation source and the radiation detector from the vehicle on the vehicle;

(b) directing incident radiation onto the wheel from the radiation source and detecting radiation reflected from the wheel at the radiation detector; and

(c) processing the detected radiation to provide a radiation analysis function including information relative to a profile of the wheel.

6. Apparatus for tire condition assessment comprising:

(a) mounting means for rotatably supporting a tire to be tested;

(b) a single radiation source located for directing incident radiation as a band or stripe or line across at least a portion of the lateral width of the tire onto two or more circumferentially spaced locations on the tire to be tested so that at each of the locations on the tire the incident radiation is directed at an incident direction inclined to a tire radius at substantially the same oblique or non-zero angle;

(c) a radiation detector located for detecting radiation reflected from each of the locations on the tire, said radiation detector including means to receive radiation from at least said portion of the lateral width of the tire;

support means to support said radiation source and said radiation detector from structure of a vehicle on which the tire is mounted, and

(d) a signal processor connected to said radiation detector and adapted to provide a radiation analysis function including information relative to a profile of the tire in relation to reflected radiation detected by said detector;

(e) said signal processor inducing means adapted to determine at least one characteristic of the condition of the tire by reference to its profile including a measure of tread depth at each said peripheral location on the basis of image displacement by the tread depth.

7. Apparatus according to claim 6, wherein said signal processor includes means to perform an image analysis function in relation to the reflected radiation.

8. Apparatus according to claim 6, wherein said signal processor includes means to effect an intensity analysis function in relation to the reflected radiation.

9. Apparatus according to claim 6, wherein said radiation source includes a laser source, and said signal processor includes means to effect an image displacement analysis function in relation to the reflected radiation.

10. Apparatus according to claim 6, wherein said signal processor includes means to develop a profile of the tire from tread determinations at a plurality of locations.

11. Apparatus for making diagnostic and/or maintenance determinations of tire an(i/or wheel data on an automotive vehicle tire and/or wheel without removing same from the vehicle, comprising:

a radiation source, a radiation detector, mounting apparatus for mounting the source and the detector on the vehicle adjacent to the tire and/or wheel in a position for directing incident radiation onto the tire and/or wheel and detecting radiation reflected from the tire and/or wheel, and a processor coupled to the detector and adapted to provide a radiation analysis function including information relative to a profile of the tire and/or wheel in relation to reflected radiation detected by the detector.

12. Apparatus for tire condition assessment comprising:

(a) mounting means for rotatably supporting a tire to be tested;

(b) a radiation source located for directing incident radiation onto the tire to be tested;

(c) a radiation detector located for detecting radiation reflected from the tire;

(d) reflection means providing a planar reflection surface lying in a plane spaced from the tire and of known attitude with respect to the apparatus for reflecting a portion of said incident radiation for use as a reference base for positional analysis of the tire during tire condition assessment; and

(e) a signal processor connected to said radiation detector and adapted to provide a radiation analysis function including information relative to a profile of the tire in relation to reflected radiation detected by said detector;

(f) said signal processor including means adapted to determine at least one characteristic of the condition of the tire by reference to its profile.

13. Apparatus according to claim 12, wherein said surface of known attitude includes a window and said reflected portion of said radiation is an internally reflected portion thereof.

14. Apparatus according to claim 12, further comprising abutment means engageable with the tire to enable a defined proximity to be established between said apparatus and the tire.

15. Apparatus according to claim 12, further comprising means supporting said abutment means in use between said window and the tire.

16. Apparatus according to claim 12, wherein said abutment means includes a pair of alignment bars disposed over said window for simultaneous abutting engagement with the tire in use.