Automatic error recognition apparatus

• US 5,903,663 A
• Filed: 02/15/1996
• Issued: 05/11/1999
• Est. Priority Date: 02/15/1995
• Status: Expired due to Term

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Tiede GmbH & Company Risprufanlagen
• Inventors: Abend, Klaus
• Primary Examiner(s): Kelley, Christopher S.
• Application Number:
  US08/602,156
• Time in Patent Office: 1,181 Days
• Field of Search: 382/108, 382/141, 382/149, 382/152, 382/153, 382/154, 348/86, 348/92, 348/94, 348/95, 348/125, 348/128-130, 348/159, 348/47, 348/48, 356/237, 356/12, 364/468, 364/474, 364/5, 364/474.12, 250/558, 250/561-563, 219/121.64, 29/703, 29/709, 29/710, 395/119, 901/9, 901/16, 901/47
• US Class Current: 382/152
• CPC Class Codes: G01N 21/91 using penetration of dyes, e.g. fluorescent ink
• CPC Class Codes: G01N 27/84 by applying magnetic powder or magnetic ink

Abstract

An apparatus and process for automatic error recognition for testing for tears in a magnetic-powder process during in-process control of image processing, whereby image recording units together with a downstream image processing unit evaluate areas with different optical characteristics from selected sample surface segments. In the process, a robot gasps at least one of the passing samples in precise position and brings the sample into a three-dimensional testing apparatus with image recording units arranged three-dimensionally, whereby the robot places the sample in precise position into the three-dimensional testing apparatus. The sample is then photographed by the image recording units which then transmit the obtained image information to a computer for evaluation. This computer is able to direct the robot accordingly based on its evaluation.

Claims

1. An automatic error recognition apparatus for automatically detecting and evaluating cracks in unitary objects during in-process testing by image recognition, the unitary objects being coated with a magnetic powder capable of fluorescence or with black powder which accumulates in any unitary cracks of the objects, the system comprising:

a three-dimensional testing apparatus including image recording means for obtaining images of selected segments of a surface on at least two sides of the unitary objects,

ultraviolet lamps for illuminating the unitary objects in conjunction with the recordation of the images by said image recording means such that in the images, any magnetic power or black powder accumulated in cracks in the unitary objects contrasts with the surfaces of the unitary objects,

a robot for transferring the unitary objects into and from said testing apparatus such that when the unitary objects are in said testing apparatus, said robot holds the unitary objects in precise, preselected positions relative to said image recording means to enable said image recording means to obtain images of the selected surface segments on said at least two sides of the unitary objects, and

image processing means coupled to said image recording means for receiving the images of the selected surface segments on said at least two sides of the unitary objects from said image recording means, said image processing means comprising a computer structured and arranged to evaluate the images of the selected surface segments for the presence of cracks in the selected surface segments to thereby detect any cracks in the selected surface segments, said image processing means being coupled to said robot to control actions of said robot with respect to the transfer of the unitary objects from said testing apparatus based on the evaluation of the images of the selected surface segments by said image processing means.

2. The apparatus of claim 1, wherein said testing apparatus comprises a three-dimensional framework, said image recording means being mounted in connection with said framework to obtain images of the selected surface segments on said at least two sides of the objects each from a different direction.

3. The apparatus of claim 2, wherein said framework comprises a plurality of discrete modular components, said modular components being assemblable in different configurations to provide a variety of testing configurations depending on the geometry of the objects.

4. The apparatus of claim 1, further comprising a marking device coupled to said image processing means for marking areas of the selected surface segments.

5. The apparatus of claim 1, further comprising a post-treatment device arranged at a different location than a location at which said testing apparatus is situated said post-treatment device being coupled to said image processing means for reworking the objects in accordance with the evaluation of the images of the selected surface segments by said image processing means.

6. The apparatus of claim 5, wherein said robot is structured and arranged to transfer the samples to said post-treatment device.

15. The apparatus of claim 1, wherein said image recording means comprise a plurality of cameras, each of said cameras providing an image of the surface on a respective side of the objects to thereby obtain images from all sides of the objects.

16. The apparatus of claim 1, wherein said image recording means comprise a plurality of cameras, each of said cameras being oriented toward the objects to provide an image of the object from a different direction.

7. In an apparatus for testing for the presence of cracks in unitary objects including image recording means for recording an image of a surface of each unitary object and image processing means for evaluating the recorded images of the surface of the unitary objects to determine the presence of cracks in the surface of the unitary objects, the unitary objects being coated with a magnetic powder capable of fluorescence or with black powder which accumulates in any unitary cracks of the objects the improvement comprising:

a three-dimensional framework comprising a plurality of modular components forming a plurality of modules in which a respective one of the unitary objects is positionable, said modules being assembled in a specific pattern in accordance with the geometry of the unitary objects being tested,

said image recording means being arranged on said framework to obtain and record images of surfaces on at least two sides of the unitary objects and said image processing means being structured and arranged to evaluate the presence of cracks in the surfaces on said at least two sides of the unitary objects and thereby detect any cracks in the surface of the unitary objects, and

ultraviolet lamps for illuminating the unitary objects in conjunction with the recordation of the images of surfaces on at least two sides of the unitary objects by said image recording means such that in the images, any magnetic power or black powder accumulated in cracks in the unitary objects contrasts with the surfaces of the unitary objects.

8. The testing apparatus of claim 7, further comprising lighting means coupled to said modular components for illuminating the objects in said modules.

17. The testing apparatus of claim 7, wherein said image recording means comprise a plurality of cameras, each of said cameras providing an image of a respective side of the objects to thereby obtain images from all sides of the objects.

18. The testing apparatus of claim 7, wherein said image recording means comprise a plurality of cameras, each of said cameras being oriented toward the objects to provide an image of the object from a different direction.

9. A process for automatic error recognition in checking for tears in surfaces of unitary objects, comprising the steps of:

grasping in precise position each of the unitary objects by means of a robot,

conveying the unitary objects into a three-dimensional testing apparatus,

coating the unitary objects with a magnetic powder such that the magnetic powder accumulates in any cracks in the unitary objects,

recording images of surface segments on at least two sides of the unitary objects while the unitary objects are present in the testing apparatus,

illuminating the unitary objects by means of ultraviolet lamps in conjunction with the recordation of the images of surface segments on at least two sides of the objects such that in the images, any magnetic power or black powder accumulated in cracks in the unitary objects contrasts with the surfaces of the unitary objects,

processing the images of the unitary objects to evaluate the presence or absence of cracks in the surface segments on said at least two sides of the unitary objects, and

controlling movement of the robot to transfer the unitary objects from the testing apparatus based on the evaluation of the presence or absence of cracks in the surface segments on said at least two sides of the unitary objects.

10. The process of claim 9, further comprising the step of directing the robot to transfer the objects with cracks to a reworking station.

11. The process of claim 9, further comprising the step of directing the robot to transfer the objects with cracks to a production station.

12. The process of claim 9, wherein the object is a calibration sample of the object with predetermined defects.

13. The process of claim 9, wherein the unitary objects are coated with the magnetic powder prior to the step of grasping the objects by means of the robot.

14. The process of claim 9, wherein the unitary objects are coated with the magnetic powder after the step of grasping by the robot and prior to the step of conveying the objects into the testing apparatus.

19. The process of claim 9, wherein said step of recording images comprises the step of positioning a plurality of cameras to provide an image of a respective side of the objects, and orienting the cameras toward the objects to provide an image of the object from a different direction.