System for identifying defects in a composite structure

• US 6,871,684 B2
• Filed: 08/13/2002
• Issued: 03/29/2005
• Est. Priority Date: 08/13/2002
• Status: Expired due to Term

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Engelbart, Roger W., Walters, Craig
• Primary Examiner(s): Fiorilla, Chris
• Assistant Examiner(s): KOCH, GEORGE R
• Application Number:
  US10/217,805
• Publication Number:
  US 20040031567A1
• Time in Patent Office: 959 Days
• Field of Search: 156/378, 156/379, 156166-174, 156176-181, 156184-195, 156/350, 156/352, 156/358, 156/367, 356/300, 356/324, 356/237.2
• US Class Current: 156/361
• CPC Class Codes: G01N 2021/8472 Investigation of composite materials
• CPC Class Codes: G01N 2021/888 Marking defects
• CPC Class Codes: G01N 21/88 Investigating the presence of flaws or contamination
• CPC Class Codes: G01N 21/8806 Specially adapted optical and illumination features
• CPC Class Codes: G01N 2201/0618 Halogene sources
• CPC Class Codes: G01N 2201/0634 Diffuse illumination
• CPC Class Codes: G01N 2201/0636 Reflectors

Abstract

The present invention provides an improved system for identifying defects in a composite structure by providing a light source such that defects, and in particular dark defects on a dark background and/or light defects on a light background, can be identified by capturing images of the illuminated composite structure. In particular, the improved system for identifying defects in a composite structure may provide a reflective surface, dispersion elements, and multiple and/or moveable light source(s) and/or camera(s) in order to ensure that the most accurate images of any area of the composite structure, even curved or contoured areas, are captured and processed. As a result, the system of the present invention permits the operator to quickly identify and correct defects which would otherwise create structural flaws or inconsistencies that may affect the integrity of the composite structure.

Claims

1. A system for identifying defects in a composite structure during fabrication thereof, comprising:

a light source positioned relative to the composite structure for illuminating the composite structure, wherein light generated by said light source is reflected differently by defects in the composite structure than from portions of the composite structure that are defect free;

a dispersion element proximate said light source for scattering the light generated by said light source over the composite structure, wherein said dispersion element comprises a reflective surface having a stepped configuration to more evenly scatter the light over the composite structure;

a reflective surface proximate the composite structure and directed toward a portion of the composite structure that is illuminated; and

a camera directed toward said reflective surface to receive images of that portion of the composite structure that is illuminated following reflection of the image from said reflective surface.

2. The system of claim 1, wherein said camera is positioned further from the illuminated portion of the composite structure than said reflective surface.

3. The system of claim 1, wherein said reflective surface is a mirror.

4. The system of claim 1, wherein said reflective surface comprises a plurality of reflective surfaces that cooperate to direct the images to the camera.

5. The system of claim 1, wherein said camera is an infrared-sensitive camera.

6. The system of claim 1, wherein said camera is a visible light camera with infrared-pass filtration.

7. The system of claim 1, wherein said light source is a halogen light.

8. The system of claim 1, wherein said camera is moveable relative to the composite structure.

9. The system of claim 1, wherein said camera comprises a plurality of cameras located at different respective positions relative to the composite structure.

10. The system of claim 1, wherein said light source is moveable relative to the composite structure.

11. The system of claim 1, wherein said light source comprises a plurality of light sources located at different respective positions relative to the composite structure.

12. The system of claim 1, further comprising a marking device for indicating the defects on the composite structure.

13. The system of claim 1, further comprising a processor for processing the images and outputting a response identifying a defect based upon the images.

14. The system of claim 1, wherein the composite structure comprises a plurality of composite strips, said composite strips being laid down by an automated collation process in which the composite strips are provided by a head unit and compacted to the underlying composite structure by a compaction roller, and wherein said reflective surface and said light source are proximate the compaction roller.

15. The system of claim 14, wherein said reflective surface and said light source are mounted on said head unit.

16. The system of claim 1 wherein the dispersion element comprises a plurality of steps extending parallel to said light source.

17. A system for identifying defects in a composite structure during fabrication thereof, comprising:

a light source positioned relative to the composite structure for illuminating the composite structure, wherein light generated by said light source is reflected differently by defects in the composite structure than from portions of the composite structure that are defect free;

a dispersion element proximate said light source for scattering the light generated by said light source over the composite structure, wherein said dispersion element comprises a reflective surface having a stepped configuration to more evenly scatter the light over the composite structure; and

a camera for receiving images of a portion of the composite structure that is illuminated.

18. The system of claim 17 wherein the dispersion element comprises a plurality of steps extending parallel to said light source.

19. A system for identifying defects in a composite structure during fabrication thereof, comprising:

a light source positioned relative to the composite structure for illuminating the composite structure, wherein light generated by said light source is reflected differently by defects in the composite structure than from portions of the composite structure that are defect free;

a dispersion element proximate said light source for scattering the light generated by said light source over the composite structure, wherein said dispersion element has a modified parabolic shape about said light source, and wherein said dispersion element has a stepped configuration arranged in a parabolic shape to more evenly scatter the light over the composite structure; and

a camera for receiving images of a portion of the composite structure that is illuminated.

20. The system of claim 19, wherein said dispersion element is at least partially curved toward said light source.

21. The system of claim 19, wherein said dispersion element is adjustable relative to the composite structure, such that said dispersion element scatters the light over a predetermined portion of the composite structure from which said camera receives images.

22. The system of claim 19, wherein said camera is an infrared-sensitive camera.

23. The system of claim 19, wherein said camera is a visible light camera with infrared-pass filtration.

24. The system of claim 19, wherein said light source is a halogen light.

25. The system of claim 19, wherein said camera is moveable relative to the composite structure.

26. The system of claim 19, wherein said camera comprises a plurality of cameras located at different respective positions relative to the composite structure.

27. The system of claim 19, wherein said light source is moveable relative to the composite structure.

28. The system of claim 19, wherein said light source comprises a plurality of light sources located at different respective positions relative to the composite structure.

29. The system of claim 19, further comprising a marking device for indicating the defects on the composite structure.

30. The system of claim 19, further comprising a processor for processing the images and outputting a response identifying a defect based upon the images.

31. The system of claim 19, wherein the composite structure comprises a plurality of composite strips, said composite strips being laid down by an automated collation process in which the composite strips are provided by a head unit and compacted to the underlying composite structure by a compaction roller, and wherein said camera and said light source are proximate the compaction roller.

32. The system of claim 31, wherein said camera, said light source and said dispersion element are mounted on said head unit.

33. A system for identifying defects in a composite structure during fabrication thereof, comprising:

a light source positioned relative to the composite structure for illuminating the composite structure, wherein light generated by said light source is reflected differently by defects in the composite structure than from portions of the composite structure that are defect free;

a camera for receiving images of a portion of the composite structure that is illuminated; and

a dispersion element proximate said light source for directing the light generated by said light source toward the composite structure, wherein said dispersion element has a stepped configuration to more evenly distribute the light over the composite structure.

34. The system of claim 33, wherein said camera is an infrared-sensitive camera.

35. The system of claim 33, wherein said camera is a visible light camera with infrared-pass filtration.

36. The system of claim 33, wherein said light source is a halogen light.

37. The system of claim 33, wherein said camera comprises a plurality of cameras located at different respective positions relative to the composite structure.

38. The system of claim 33, wherein said light source comprises a plurality of light sources located at different respective positions relative to the composite structure.

39. The system of claim 33, further comprising a marking device for indicating the defects on the composite structure.

40. The system of claim 33, further comprising a processor for processing the images and outputting a response identifying a defect based upon the images.

41. The system of claim 33, wherein the composite structure comprises a plurality of composite strips, said composite strips being laid down by an automated collation process in which the composite strips are provided by a head unit and compacted to the underlying composite structure by a compaction roller, and wherein said camera and said light source are proximate the compaction roller.

42. The system of claim 33 wherein the dispersion element comprises a plurality of steps extending parallel to said light source.