Tire surface anomaly detection

• US 9,029,779 B2
• Filed: 06/15/2010
• Issued: 05/12/2015
• Est. Priority Date: 06/15/2010
• Status: Expired due to Fees

• 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: Estor, Patrice R., Nicholson, Verner Steve, Thomas, Anton Felipe, De Amicis, Gene Edward, Gramling, Frank E., Judd, David Andrew, Schober, Bradley D., Flament, Julien Matthieu
• Primary Examiner(s): Porta, David
• Assistant Examiner(s): GUNBERG, EDWIN C
• Application Number:
  US13/704,436
• Publication Number:
  US 20130099123A1
• Time in Patent Office: 1,792 Days
• Field of Search: 250/341.6
• US Class Current: 250/341.6
• CPC Class Codes: G01M 17/027 using light, e.g. infrared, ultraviolet or holographic techniques
• CPC Class Codes: G01N 21/95 characterised by the material or shape of the object to be examined G01N21/89 - G01N21/91, G01N21/94 take precedence
• CPC Class Codes: G06T 2207/10048 Infrared image
• CPC Class Codes: G06T 7/0004 Industrial image inspection

Abstract

A tire surface anomaly detection system and method are disclosed. The system and method are generally based on the principle that a tire surface anomaly will have a different heat transfer rate than that of the uniform mass surrounding the tire surface anomaly. Embodiments of the present disclosure apply thermal energy to the surface of a tire and monitor the infrared energy at the surface of the tire to generate one or more infrared images of the surface of the tire. The infrared images are analyzed by an image processing system to determine and locate thermal gradients on the surface of the tire. The presence of a thermal gradient in the infrared images generally indicates the presence of an anomaly in the surface of the tire. In this manner, the present disclosure provides an objective technique for identifying, locating, and classifying tire surface anomalies.

Claims

1. A tire inspection method, comprising:

imparting motion to a tire with a tire rotation device to present a first portion of a tire inner surface to a thermal energy source;

providing thermal energy from the thermal energy source to the first portion of the tire surface;

imparting motion to the tire with the tire rotation device to present the first portion of the tire inner surface to an infrared detector, the infrared detector being separated from the thermal energy source by an angular distance based on a center of the tire in the range of 5°

to 30°

;

detecting infrared energy from the first portion of the tire inner surface with the infrared detector;

generating a first infrared image of the first portion of the tire inner surface based at least in part on the infrared energy detected from the first portion of the tire inner surface; and

analyzing the first infrared image with an image processing system using image subtraction to determine the presence of one or more anomalies in the tire inner surface;

wherein imparting motion to the tire comprises continuously rotating the tire inner surface over the thermal energy source and the infrared detector.

2. The tire inspection method of claim 1, wherein providing thermal energy from the thermal energy source comprises heating or cooling the first portion of the tire inner surface.

3. The tire inspection method of claim 1, wherein the method comprises adjusting the location of the thermal energy source relative to the infrared detector to reduce washout effects in the first infrared image.

4. The tire inspection method of claim 1, wherein the infrared detector detects infrared energy from a scan window at the tire inner surface, the method further comprising rotating the infrared detector so that the scan window moves laterally across the tire inner surface.

5. The tire inspection method of claim 1, wherein the infrared detector is configured to detect infrared energy from a scan window at the tire surface, the scan window having a size of about 25 mm×

25 mm at the tire inner surface.

6. The tire inspection method of claim 1, wherein the first infrared image comprises a plurality of pixels, each pixel having a pixel value associated with a temperature of the tire inner surface.

7. The method of claim 6, wherein analyzing the first infrared image with an image processing system comprises performing a pixel thresholding analysis to determine the presence of one or more high or low pixel value regions in the first infrared image.

8. The method of claim 1, wherein the method comprises:

storing the first infrared image into a memory;

imparting motion to the tire to present a second portion of the tire inner surface to the thermal energy source;

providing thermal energy from the thermal energy source to the second portion of the tire inner surface;

imparting motion to the tire to present the second portion of the tire inner surface to the infrared detector;

detecting infrared energy with the infrared detector from the second portion of the tire inner surface; and

generating a second infrared image of the second portion of the tire inner surface based at least in part on infrared energy detected from the second portion of the surface of the tire.

9. The method of claim 8, wherein analyzing the first infrared image with the image processing system comprises:

performing image subtraction to the first infrared image based on the second infrared image; and

performing a thresholding analysis on the first infrared image to determine the presence of one or more high or low pixel value regions in the first infrared image.

10. A tire inspection system, comprising:

a thermal energy source positioned to provide thermal energy to a first portion of a tire inner surface;

an infrared detector separated from the thermal energy source by an angular distance based on a center of the tire in the range of 5°

to 30°

, said infrared detector configured to detect infrared energy from the first portion of the tire inner surface and to generate a first infrared image based at least in part on the infrared energy detected from the first portion of the tire inner surface;

a tire rotation device configured to continuously rotate the tire inner surface over the thermal energy source and the infrared detector; and

an image processing system coupled to the infrared detector, the image processing system configured to analyze the first infrared image using image subtraction to determine the presence of one or more anomalies in the tire inner surface.

11. The tire inspection system of claim 10, wherein the thermal energy source comprises a quartz heater.

12. The tire inspection system of claim 11, wherein the output of the quartz heater is about 600W.

13. The tire inspection system of claim 10, wherein the tire inner surface is placed over the thermal energy source and the infrared detector when the tire is received onto the tire rotation device.

14. The tire inspection system of claim 10, wherein the infrared detector comprises an infrared camera.

15. The tire inspection system of claim 10, wherein the infrared detector comprises a plurality of photoelectric diodes sensitive to infrared energy.

16. The tire inspection system of claim 10, wherein the infrared detector is configured to detect infrared energy from a scan window at the tire surface, the scan window having a size of approximately 25 mm×

25 mm at the tire inner surface.

17. The tire inspection system of claim 10, wherein the image processing system is configured to perform a thresholding analysis on the first infrared image to determine the presence of one or more high pixel regions in the first infrared image.

18. The tire inspection system of claim 10, wherein the infrared detector is configured to detect infrared energy from a second portion on the tire inner surface and to generate a second infrared image based at least in part on the infrared energy detected from the second portion of the tire inner surface.

19. The tire inspection system of claim 18, wherein the image processing system is configured to perform image subtraction on the first infrared image based at least in part on the second infrared image.