In-process vision detection of flaw and FOD characteristics
An inspection system ( 9 ) includes an idler wheel ( 61 ) that is coupled to a fabrication system ( 8 ) and is in contact with a backing layer ( 65 ) of an applied material ( 64 ), A rotation sensor ( 63 ) monitors the idler wheel ( 61 ) and generates a rotational signal. A controller ( 24 ) is coupled to the rotation sensor ( 63 ) and determines a characteristic of one or more flaws and FOD ( 19 ) on a composite structure ( 12 ) in response to the rotation signal.
1. A method of determining flaw and FOD characteristics comprising:
rotating an idler wheel via a backing layer of a composite material;
monitoring said idler wheel and generating a rotational signal; and
determining at least one characteristic of at least one flaw and FOD on a portion of a composite structure in response to said rotation signal using a controller, wherein the controller stores the at least one characteristic of the at least one flaw and FOD for use in correcting the at least one flaw and FOD.
2. A method as in claim 1 further comprising:
acquiring images via at least one detector,
counting images to generate an image count; and
determining a linear distance along a composite structure in response to said image count.
3. The method as in claim 2 further comprising illuminating said composite structure.
4. The method as in claim 2 further comprising storing said images.
5. The method of claim 2 further comprising synchronizing said acquiring of images with said rotating of idler wheel.
6. The method of claim 2 further comprising blocking wavelengths of visible light from entering said at least one detector via at least one filter.
7. A method as in claim 1 further comprising:
counting revolutions of said idler wheel to generate a revolution count; and
determining a linear distance along a composite structure in response to said revolution count.
8. A method as in claim 1 wherein said at least one characteristic comprises at least one of size, location, position, type, density-per-unit area, and cumulative defect width-per-unit area.
9. A method as in claim 1 further comprising:
counting revolutions of said idler wheel to generate a revolution count;
counting cessations of said idler wheel to generate a cessation count; and
determining position of said at least one flaw and FOD in response to said revolution count and said cessation count.
10. A method as in claim 9 further comprising:
counting applied layers of said composite structure to generate an applied layer count; and
determining location of said at least one flaw and FOD in response to said revolution count, said cessation count, and said applied layer count.
11. A method as in claim 1 further comprising:
determining size of said at least one flaw and FOD; and
determining flaw area density in response to said portion and said size.
12. A method as in claim 1 further comprising:
counting said at least one flaw and FOD in a current frame and course to generate a current flaw and FOD frame count;
summing said current flaw and FOD frame count with flaws and FOD of two adjacent frames of a previous course to generate a resultant sum; and
determining flaw areal density for said portion in response to said resultant sum.
13. A method as in claim 1 further comprising:
determining size of said at least one flaw and FOD; and
determining cumulative gap width per unit area in response to said portion and said size.
14. A method as in claim 1 further comprising:
dividing said composite structure into a plurality of unit areas; and
determining said characteristic in response to said division.
15. A method as in claim 14 further comprising assigning angular cut frames of said plurality of unit areas a full frame unit area.
16. A method as in claim 1 further comprising altering operation of a fabrication system in response to said at least one characteristic.
17. A method as in claim 1 wherein determining at least one characteristic comprises determining cumulative gap width through summation of a plurality of gaps laterally across said portion perpendicular to a direction of material placement.
18. A method as in claim 17 wherein summing said plurality of gaps comprises assigning gap lengths to extend approximately an entire frame length.
19. A method as in claim 1 further comprising:
staggering frames; and
determining said at least one characteristic in response to said frame stagger.
20. The method of claim 1 further comprising using data stored by the controller to adjust operation of at least one of a fabrication system, an inspection system, and a lamination system to correct the at least one characteristic of the at least one flaw and FOD.