Method for inspecting an automotive wheel and associated apparatus

• US 6,831,996 B1
• Filed: 09/24/2001
• Issued: 12/14/2004
• Est. Priority Date: 09/24/2001
• Status: Expired due to Fees

• Current Assignee: Oberg Industries
• Original Assignee: Oberg Industries
• Inventors: Williams, David B., Gephardt, Robert J., Rummel, Samuel A.
• Primary Examiner(s): Chang, Jon
• Assistant Examiner(s): KIM, CHONG R
• Application Number:
  US09/961,655
• Time in Patent Office: 1,177 Days
• Field of Search: 382/141, 382/143, 382/152, 382/291, 348/86, 348/125
• US Class Current: 382/141
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 7/73 using feature-based methods
• CPC Class Codes: G06V 10/245 by locating a pattern; Special marks for positioning

Abstract

A method of inspecting an automotive wheel includes providing an inspection station having a light source for illuminating the wheel, and a camera having a zoom lens. The automotive wheel is positioned in the inspection station and the wheel is illuminated to generate a first image including the reference feature. After the first image information has been delivered to the processor, the model of the automotive wheel is determined on the basis of data stored in the processor and the parameters to be used during the inspection of the particular model are employed in the subsequent inspection. The processor determines the position of the reference feature and determines whether the automotive wheel is in the desired position. If not, the wheel is rotated to move the reference feature toward the desired position. The light source, camera and zoom lens are then moved to a second position closer to the reference feature and a zoomed second image of the automotive wheel is obtained with the image second information being compared in the processor with the desired reference position location. If the reference feature is not in the desired position, the processor initiates further rotation to move the reference feature to the desired position. The zoomed second image has a smaller field of view than the first image. Related apparatus is also disclosed.

Claims

1. A method of inspecting an automotive wheel having a reference feature comprising,

providing an inspection station having a light source for illuminating

said wheel and a camera having a zoom lens,

positioning an automotive wheel in said inspection station and illuminating said wheel with said light source,

employing said camera to obtain a first image providing first image information of said wheel from a first position and delivering image information to a processor,

employing said processor to determine the position of said reference feature and if it is not in the desired position rotating said automotive wheel to move said reference feature toward said desired position,

moving said light source camera and zoom lens to a second position closer to said reference feature,

employing said camera to obtain a second image of said automotive wheel and providing second image information to said processor, and

employing said processor to determine the position of said reference feature and if it is not in the desired position rotating said automotive wheel to move said reference feature to said desired position.

2. The method of inspecting an automotive wheel of claim 1 including,

obtaining said first image with said zoom lens in a first position, and

obtaining said second image with said zoom lens in a second position closer to said wheel than said first position.

3. The method of inspecting an automotive wheel of claim 1 including,

effecting said movement of said light source, camera and zoom lens from said first position to said second position through linear movement thereof.

4. The method of inspecting an automotive wheel of claim 2, including

employing said first image information to determine which model automotive wheel is being inspected, and

employing said processor to effect said inspection in accordance with parameters programmed for said specific model.

5. The method of inspecting an automotive wheel of claim 4, including

repeating said cycle with a plurality of automotive wheels at least some of which are of a different model without requiring a physical change in the structure of said inspection station.

6. The method of inspecting an automotive wheel of claim 5, including

after said automotive wheel inspection delivering said automotive wheel to a first work station while preserving the orientation of said automotive wheel reference feature.

7. The method of inspecting an automotive wheel of claim 1, including

providing said processor with a signal confirming the presence of said automotive wheel to be inspected within said inspection station before initiating said inspection.

8. The method of inspecting an automotive wheel of claim 7, including

subsequent to said confirmation of said automotive wheel being disposed within said inspection station but prior to obtaining said first image elevating said automotive wheel.

9. The method of inspecting an automotive wheel of claim 8, including

positioning said automotive wheel generally horizontally during said inspection.

10. The method of inspecting an automotive wheel of claim 9, including

providing a controller for controlling operation of portions of the inspection system responsive to signals received by said controller from said processor.

11. The method of inspecting an automotive wheel of claim 1, including

employing as said light source an annular florescent light source.

12. The method of inspecting an automotive wheel of claim 1, including

obtaining said first image with substantially the entire upper surface of said automotive wheel including said reference feature being included, and

obtaining said second image with less than the entire upper surface being included.

13. The method of inspecting an automotive wheel of claim 2, including

positioning said zoom lens in said obtaining of said second image being positions closer to said automotive wheel than in obtaining said first image.

14. The method of inspecting an automotive wheel of claim 1, including

obtaining said second image employing a smaller field of view than was employed in obtaining said first image.

15. The method of inspecting an automotive wheel of claim 1, including

positioning said camera and said zoom lens substantially along the center of the central axis of said wheel when obtaining said first image.

16. The method of claim 1 including employing two said reference features.

17. The method of claim 1 including employing as a said reference feature at least one projection.

18. The method of claim 1 including employing as a said reference feature at least one recess.

19. Apparatus for inspecting an automotive wheel having a reference feature comprising

an automotive wheel support for receiving, elevating and rotating said automotive wheel,

a light source overlying said automotive wheel support,

a camera and zoom lens overlying said automotive wheel support,

a processor for receiving first image information from a first image of substantially the entire upper surface of said automotive wheel, and effecting a comparison between the desired position of said reference feature and the actual position thereof and if the desired feature is not in the desired position initiating rotation of said automotive wheel to move said reference feature toward said desired position, and

said processor being structured to receive second image information from a second image of a portion of said automotive wheel including said reference feature and effecting a comparison between the desired reference feature position and the actual reference feature position and if the reference feature is not in the desired position, initiating rotation of said automotive wheel to move said reference position to said desired position, and an actuator for moving said light source, said camera and zoom lens between a first position for obtaining said first image and a second position for obtaining said second image, wherein said second position is closer to the reference feature than said first position.

20. Apparatus for inspecting an automotive wheel of claim 19 including,

said processor being structured on the basis of said first image information to determine the model of said automotive wheel and employ stored information regarding the same during said inspection.

21. Apparatus for inspecting an automotive wheel of claim 20 including,

a controller for effecting operation of the system components responsive to output signals received from said processor.

22. Apparatus for inspecting an automotive wheel of claim 21 including,

a conveyor for delivering a plurality of automotive wheels to said automotive wheel support sequentially.

23. Apparatus for inspecting an automotive wheel of claim 22 including,

said conveyor being structured to deliver said automotive wheels in a generally horizontal orientation.

24. Apparatus for inspecting an automotive wheel of claim 23 including,

a photo-detector for confirming the presence of an automotive wheel to be inspected.

25. Apparatus for inspecting an automotive wheel of claim 19 including,

said camera and said zoom lens having a smaller field of view in obtaining said second image than in obtaining said first image.

26. Apparatus for inspecting an automotive wheel of claim 19 including,

said light source being an annular florescent light source.

27. Apparatus for inspecting an automotive wheel of claim 19 including,

said camera and said zoom lens being centered over said automotive wheel support when said first image is obtained.

28. Apparatus for inspecting an automotive wheel of claim 19 including,

said actuator being structured to move said light source, said camera and said zoom lens in a generally linear path.

29. Apparatus for inspecting an automotive wheel of claim 28 including

an automotive wheel receiver for removing an inspected automated wheel, and

delivering it to a first work station while maintaining the angular position of said reference feature.

30. Apparatus for inspecting an automotive wheel of claim 19 including said automotive wheel support being structured to project upwardly into said wheel.