Systems and methods for fiber placement inspection during fabrication of fiber-reinforced composite components

Patent metadata

Field	Value
Publication number	US-9759547-B2
Application number	US-201414463433-A
Country	US
Kind code	B2
Filing date	Aug 19, 2014
Priority date	Aug 19, 2014
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

The disclosed systems and methods relate to inspecting uncured fiber-reinforced composite components by non-contact 3D measurements of the component using 3D digital image correlation with patterned illumination. Systems comprise a light projector configured to project a light pattern onto a form, a digital camera configured to image the light pattern, and may comprise and/or be associated with an AFP machine that is configured to lay uncured composite on the form. Methods comprise projecting a light pattern onto a form, acquiring a baseline 3D profile of the form by imaging the light pattern on the form, laying an uncured fiber piece onto the form, projecting the light pattern onto the uncured fiber piece, acquiring a test 3D profile of the fiber piece by imaging the light pattern on the uncured fiber piece, and computing a thickness difference between the test 3D profile and the baseline 3D profile.

First claim

The invention claimed is:

1. An inspection method comprising:
projecting a light pattern onto an inspection area on a form;
acquiring a baseline 3D profile of the form by imaging the light pattern on the form from different perspectives and performing digital image correlation with images of the form from the different perspectives;
laying an uncured fiber piece onto the form within the inspection area;
projecting the light pattern onto the uncured fiber piece on the form;
acquiring a test 3D profile of the uncured fiber piece on the form by imaging the light pattern on the uncured fiber piece on the form from the different perspectives and performing digital image correlation with images of the uncured fiber piece from the different perspectives; and
computing a thickness difference between the test 3D profile and the baseline 3D profile.

2. The inspection method of claim 1 , wherein the acquiring the baseline 3D profile and the acquiring the test 3D profile include performing full-field 3D image correlation.

3. The inspection method of claim 1 , further comprising detecting a void between the uncured fiber piece and the form.

4. The inspection method of claim 1 , further comprising detecting no void between the uncured fiber piece and the form.

5. The inspection method of claim 1 , wherein the light pattern includes bright patches bounded by dim patches.

6. The inspection method of claim 1 , wherein the projecting the light pattern onto the form includes focusing an image of the light pattern on the form, and wherein the projecting the light pattern onto the uncured fiber piece on the form includes focusing an image of the light pattern on the uncured fiber piece on the form.

7. The inspection method of claim 1 , wherein the images form from the different perspectives include at least two baseline images of the light pattern on the form, and wherein the images of the uncured fiber piece from the different perspectives include at least two test images of the light pattern on the form.

8. The inspection method of claim 1 , wherein the acquiring the baseline 3D profile includes substantially simultaneously imaging, with at least two digital cameras with the different perspectives, the light pattern on the form, and wherein the acquiring the test 3D profile includes substantially simultaneously imaging, with the at least two digital cameras, the light pattern on the uncured fiber piece on the form.

9. The inspection method of claim 1 , wherein the images of the form from the different perspectives include a first image of the light pattern on the form from a first perspective and a second image of the light pattern on the form from a second perspective, and wherein the images of the uncured fiber piece from the different perspectives include a third image of the light pattern on the uncured fiber piece on the form from the first perspective a fourth image of the light pattern on the uncured fiber piece on the form from the second perspective.

10. The inspection method of claim 1 , wherein the laying includes laying a plurality of uncured fiber pieces in a single layer on the form.

11. The inspection method of claim 1 , wherein the uncured fiber piece is one of a series of uncured fiber pieces, and the method further comprises layering the series of uncured fiber pieces onto the form.

12. The inspection method of claim 11 , wherein the layering includes forming a first layer including at least one of the series of uncured fiber pieces and forming a second layer contacting the first layer, wherein the second layer includes at least one of the series of uncured fiber pieces.

13. The inspection method of claim 11 , further comprising, upon determining that the thickness difference is greater than a predetermined threshold, ceasing the layering.

14. The inspection method of claim 1 , wherein the computing includes computing a plurality of thickness differences between the test 3D profile and the baseline 3D profile, each thickness difference corresponding to a point within the inspection area.

15. The inspection method of claim 1 , wherein the computing includes determining that the thickness difference is greater than a predetermined threshold, wherein the predetermined threshold is less than 10 mm.

16. The inspection method of claim 1 , further comprising, upon determining that the thickness difference is greater than a predetermined threshold, compacting the uncured fiber piece onto the form.

17. The inspection method of claim 1 , further comprising, upon determining that the thickness difference is greater than a predetermined threshold, heating the uncured fiber piece.

18. A non-transitory computer-readable medium storing instructions for a computing system to perform the method of claim 1 .

19. An inspection method comprising:
projecting a light pattern onto an inspection area on a form;
acquiring a baseline 3D profile of the form by imaging the light pattern on the form, wherein the imaging includes substantially simultaneously acquiring at least two baseline images of the light pattern on the form, and wherein the acquiring the baseline 3D profile includes computing, by digital image correlation, the baseline 3D profile of the form from the baseline images;
laying an uncured fiber piece onto the form within the inspection area;
projecting the light pattern onto the uncured fiber piece on the form;
acquiring a test 3D profile of the uncured fiber piece on the form by imaging the light pattern on the uncured fiber piece on the form, wherein the imaging includes substantially simultaneously acquiring at least two test images of the light pattern on the form, and wherein the acquiring the test 3D profile includes computing, by digital image correlation, the test 3D profile of the form from the test images; and
computing a thickness difference between the test 3D profile and the baseline 3D profile;
wherein the computing includes comparing the thickness difference to a predetermined threshold that is less than 10 mm.

20. A system for inspecting an uncured fiber-reinforced composite, the system comprising:
a light projector configured to project a light pattern onto an inspection area on a form;
a digital camera configured to image the light pattern on the form; and
a computing system programmed to:
project the light pattern onto the inspection area on the form with the light projector;
acquire at least two baseline images of the light pattern on the form, wherein at least one of the two baseline images is acquired with the digital camera;
determine a baseline 3D profile of the form from the baseline images by performing digital image correlation;
project the light pattern onto the uncured fiber-reinforced composite layered on the form within the inspection area;
acquire at least two test images of the light pattern on the uncured fiber-reinforced composite layered on the form, wherein at least one of the two test images is acquired with the digital camera;
determine a test 3D profile of the uncured fiber-reinforced composite layered on the form from the test images by performing digital image correlation; and
determine a thickness difference between the test 3D profile and the baseline 3D profile.

Assignees

• Boeing Co

Inventors

• Grossnickle James A
• Mccrary Kevin Earl
• Nelson Karl M
• Cramer Craig Allen

Classifications

• G06T7/521

  from laser ranging, e.g. using interferometry; from the projection of structured light · CPC title

• G06T2207/10028

  Range image; Depth image; 3D point clouds · CPC title

• G06T7/001

  using an image reference approach · CPC title

• B32B2260/046

  Synthetic resin · CPC title

• B32B2262/106

  Carbon fibres, e.g. graphite fibres · CPC title