Methods and systems for generating a fingerprint for verification of a reference object

• US 10,262,232 B2
• Filed: 04/30/2018
• Issued: 04/16/2019
• Est. Priority Date: 08/12/2015
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Klimovski, Andrew, Szarski, Martin A.
• Primary Examiner(s): Johns, Andrew W
• Application Number:
  US15/966,079
• Publication Number:
  US 20180247157A1
• Time in Patent Office: 351 Days
• CPC Class Codes: B32B 2262/106 Carbon fibres, e.g. graphite fibres
• CPC Class Codes: B32B 5/024 Woven fabric
• CPC Class Codes: B32B 9/007 comprising carbon, e.g. graphite, composite carbon
• CPC Class Codes: G06F 18/22 Matching criteria, e.g. proximity measures
• CPC Class Codes: G06F 18/28 Determining representative reference patterns, e.g. by averaging or distorting; Generating dictionaries
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/30164 Workpiece; Machine component
• CPC Class Codes: G06T 7/001 using an image reference approach
• CPC Class Codes: G08B 21/18 Status alarms G08B21/02 takes precedence
• CPC Class Codes: H04N 23/56 provided with illuminating means

Abstract

Disclosed herein are methods and systems for generating a fingerprint for verification of a reference object, such as a layer or ply during a composite laminate layup procedure. An exemplary method includes generating a plurality of images of the reference object from a plurality of angles, removing at least one lighting effect from at least one reference image to generate at least one processed image, generating a reference fingerprint for the reference object based on the at least one processed image, generating at least one candidate image of a candidate object, generating a candidate fingerprint for the candidate object based on the at least one candidate image, comparing the candidate fingerprint and the reference fingerprint to determine whether a correlation exists between the candidate fingerprint and the reference fingerprint, and generating an alert based on the comparison of the candidate fingerprint and the reference fingerprint.

Claims

1. A method for generating a fingerprint for verification of a reference object, the method comprising:

generating a plurality of images of the reference object from a plurality of angles;

generating a light-neutral image based on a comparison of the plurality of images to each other;

generating a reference fingerprint for the reference object based on the light-neutral image;

receiving a candidate fingerprint for a candidate object based on at least one candidate image;

comparing the candidate fingerprint and the reference fingerprint to determine whether a correlation exists between the candidate fingerprint and the reference fingerprint; and

generating an alert based on the comparison of the candidate fingerprint and the reference fingerprint, wherein the alert is indicative that the correlation between the candidate fingerprint and the reference fingerprint exists.

2. The method of claim 1, wherein generating the light-neutral image comprises:

comparing the plurality of images of the reference object;

creating an image of a single view of the reference object that has bright spots removed.

3. The method of claim 2, wherein creating the image of the single view of the reference object that has bright spots removed comprises:

removing effects of specular reflection.

4. The method of claim 1, wherein generating the plurality of images of the reference object from the plurality of angles comprises generating a plurality of views of a surface of the reference object.

5. The method of claim 1, wherein the candidate fingerprint and the reference fingerprint each comprise multiple markers with a geometric relationship between the multiple markers, and wherein comparing the candidate fingerprint and the reference fingerprint to determine whether the correlation exists between the candidate fingerprint and the reference fingerprint comprises:

determining a number of markers that match between the candidate fingerprint and the reference fingerprint; and

checking whether the geometric relationship between matched markers of the candidate fingerprint and the reference fingerprint is disturbed.

6. The method of claim 5, further comprising:

determining that the candidate fingerprint and reference fingerprint match based on a proportion of given markers of the candidate fingerprint and reference fingerprint that match being above a threshold.

7. The method of claim 1, wherein generating the reference fingerprint for the reference object based on the at least one light-neutral image comprises generating the reference fingerprint based on a pattern on a surface of the reference object, and the method further comprises:

determining whether the reference object and the candidate object have the same surface pattern.

8. The method of claim 1, wherein the reference object comprises a composite laminate layer that has a specific weave pattern and/or a specific weave dimension, and the candidate object is also a composite laminate layer, and the method further comprises:

verifying that the candidate object is a proper composite laminate layer for a particular manufacturing process based on the candidate fingerprint possessing the specific weave pattern and/or the specific weave dimension.

9. The method of claim 1, further comprising:

generating the at least one candidate image of the candidate object; and

generating the candidate fingerprint for the candidate object based on the at least one candidate image.

10. The method of claim 1, further comprising:

determining if a given feature of an image of the plurality of images is statistically similar to a similar feature in other images of the plurality of images; and

if the similar feature is not present among the other images of the plurality of images, then removing the given feature from the image.

11. The method of claim 1, further comprising:

determining that the candidate object is the same object that was previously imaged as the reference object based on the comparison of the candidate fingerprint and the reference fingerprint.

12. A method for generating a fingerprint for verification of a reference object, the method comprising:

generating a plurality of images of the reference object from a plurality of angles, wherein the reference object comprises a composite laminate layer that has a specific weave pattern and/or a specific weave dimension;

generating a light-neutral image based on a comparison of the plurality of images to each other;

generating a reference fingerprint for the reference object based on the light-neutral image;

receiving a candidate fingerprint for a candidate object based on at least one candidate image, wherein the candidate object is also a composite laminate layer;

comparing the candidate fingerprint and the reference fingerprint to determine whether a correlation exists between the candidate fingerprint and the reference fingerprint; and

generating an alert based on the comparison of the candidate fingerprint and the reference fingerprint, wherein the alert is indicative that the correlation between the candidate fingerprint and the reference fingerprint exists.

13. The method of claim 12, further comprising:

verifying that the candidate object is a proper composite laminate layer for a particular manufacturing process based on the candidate fingerprint possessing the specific weave pattern and/or the specific weave dimension.

14. The method of claim 12, wherein comparing the candidate fingerprint and the reference fingerprint to determine whether the correlation exists between the candidate fingerprint and the reference fingerprint comprises:

determining whether the candidate object is substantially similar to the reference object.

15. The method of claim 12, wherein comparing the candidate fingerprint and the reference fingerprint to determine whether the correlation exists between the candidate fingerprint and the reference fingerprint comprises:

determining whether the candidate fingerprint and the reference fingerprint have a surface pattern that are the same.

16. A system for generating a fingerprint for verification of a reference object, the system comprising:

at least one detector including a plurality of lenses to receive light reflected from the reference object at a plurality of different angles, the at least one detector configured to;

generate a plurality of images of the reference object from a plurality of angles;

a signal processor configured to receive an output from the at least one detector, the signal processor configured to;

generate a light-neutral image based on a comparison of the plurality of images to each other;

generate a reference fingerprint for the reference object based on the light-neutral image;

receive a candidate fingerprint for a candidate object based on at least one candidate image;

compare the candidate fingerprint and the reference fingerprint to determine whether a correlation exists between the candidate fingerprint and the reference fingerprint; and

generate an alert based on the comparison of the candidate fingerprint and the reference fingerprint, wherein the alert is indicative that the correlation between the candidate fingerprint and the reference fingerprint exists.

17. The system of claim 16, wherein the signal processor is further configured to:

generate the reference fingerprint based on a pattern on a surface of the reference object; and

determine whether the reference object and the candidate object have the same surface pattern.

18. The system of claim 16, wherein the reference object comprises a composite laminate layer that has a specific weave pattern and/or a specific weave dimension, and the candidate object is also a composite laminate layer, and wherein the signal processor is further configured to:

verify that the candidate object is a proper composite laminate layer for a particular manufacturing process based on the candidate fingerprint possessing the specific weave pattern and/or the specific weave dimension.

19. The system of claim 16, wherein the signal processor is further configured to:

generate the at least one candidate image of the candidate object; and

generate the candidate fingerprint for the candidate object based on the at least one candidate image.

20. The system of claim 16, wherein the signal processor is further configured to:

determine if a given feature of an image of the plurality of images is statistically similar to a similar feature in other images of the plurality of images; and

if the similar feature is not present among the other images of the plurality of images, then remove the given feature from the image.