Visual Fiber Placement Inspection

Abstract

An apparatus and method are provided for performing, on-the-fly, real time inspection of a composite structure formed by an automated fiber placement machine, through comparison of a visual image of at least a portion of the composite structure to a virtual image of the composite structure. Proper formation of the structure, and/or anomalies within the structure, are determined by comparing the visual image to the virtual image. The automated fiber placement machine, and/or tooling upon which the fiber is placed, are manipulated, and a visual indicator are provided to facilitate inspection and/or repair of any detected anomalies during fabrication of the composite structure.

1 . A method for inspecting a composite structure formed from one or more composite tows by an automated fiber placement machine, the method comprising:
 providing a composite comparison device (CCD);   capturing by the CCD a visual image of at least a portion of the composite structure;   comparing by the CCD the visual image of at least a portion of the composite structure to a virtual image of the at least a portion of the composite structure.   
     
     
         2 . The method of  claim 1 , further comprising, determining proper formation of the structure, by comparing the visual image of at least a portion of the part to the virtual image of the part. 
     
     
         3 . The method of  claim 1 , further comprising, determining improper formation of the structure, by comparing the visual image of at least a portion of the structure to the virtual image of the part. 
     
     
         4 . The method of  claim 3 , further comprising manipulating the automated fiber placement machine to facilitate inspection and/or repair of the improper formation. 
     
     
         5 . The method of  claim 3 , wherein, the method includes providing a visual indication of a detected imperfection. 
     
     
         6 . The method of  claim 3 , further comprising, providing a location of the imperfection on the structure. 
     
     
         7 . The method of  claim 6 , further comprising, providing a visible indication of the location of the imperfection. 
     
     
         8 . The method of  claim 7 , wherein, the visible indication is provided by an automatically directed laser pointer. 
     
     
         9 . The method of  claim 8 , further comprising, moving the structure and/or at least a portion of the automated fiber placement machine to a position whereat the imperfection may by indicated by the laser pointer. 
     
     
         10 . The method of  claim 1 , wherein the structure is formed from one or more plies having multiple tows, and the method further includes comparing a visual image of the tows in a given ply to a virtual image of the tows in a given ply. 
     
     
         11 . The method of  claim 10 , wherein the visual image of the tows is a two dimensional profile plot of an outer surface of the tows. 
     
     
         12 . The method of  claim 1 , wherein the automated fiber placement machine includes a fiber placement head, and the visual image is taken by a vision capture element operatively connected to the fiber placement head. 
     
     
         13 . The method of  claim 12 , wherein the vision capture element is mounted on the fiber placement head. 
     
     
         14 . The method of  claim 12 , wherein the fiber placement head includes a feed roller for feeding out one or more tows of material, and the method further comprises utilizing a rotation sensor operatively connected to the feed roller for synchronization of the visual image with the virtual image. 
     
     
         15 . The method of  claim 1 , wherein one or both of the virtual image and the visual image are located along a U-axis extending through at least a portion of at least one course of material laid down by the automated fiber placement head during formation of the composite structure. 
     
     
         16 . A non-transitory computer-readable medium having computer executable instructions for performing the method of  claim 1 . 
     
     
         17 . The non-transitory computer-readable medium of  claim 16 , having further computer executable instructions for performing the step of determining proper formation of the structure, by comparing the visual image of at least a portion of the part to the virtual image of the part. 
     
     
         18 . The non-transitory computer-readable medium of  claim 16 , having further computer executable instructions for performing the step of determining improper formation of the structure, by comparing the visual image of at least a portion of the structure to the virtual image of the part. 
     
     
         19 . The non-transitory computer-readable medium of  claim 18 , having further computer executable instructions for performing the step of manipulating the automated fiber placement machine to facilitate inspection and/or repair of the improper formation. 
     
     
         20 . The non-transitory computer-readable medium of  claim 16 , having further computer executable instructions for performing the step of providing a location of the imperfection on the structure. 
     
     
         21 . The non-transitory computer-readable medium of  claim 16 , having further computer executable instructions for performing the step of providing a visible indication of the location of the imperfection. 
     
     
         22 . A method for inspecting a composite structure, formed by an automated fiber placement machine from a plurality of fiber tows laid down by the automated fiber placement machine, the method comprising:
 constructing a virtual image of the structure, prior to forming the composite structure, defining a proper placement and configuration of each of the plurality of fiber tows within the composite structure;   providing a composite comparison device (CCD);   taking a visual image of the appearance of the tows forming at least a portion of the composite structure by the CCD, in real time, as the composite structure is formed by the automated fiber placement machine; and then   comparing, by the CCD, the visual image of the appearance of the tows in the at least a portion of the structure to the proper configuration and placement of the fiber tows as defined in the virtual image of the at least a portion of the composite structure.   
     
     
         23 . The method of  claim 22 , having further computer executable instructions for performing the step of determining proper formation of the structure, by comparing the visual image of at least a portion of the part to the virtual image of the part. 
     
     
         24 . The method of  claim 22 , having further computer executable instructions for performing the step of determining improper formation of the structure, by comparing the visual image of at least a portion of the structure to the virtual image of the part. 
     
     
         25 . The method of  claim 24 , having further computer executable instructions for performing the step of manipulating the automated fiber placement machine to facilitate inspection and/or repair of the improper formation. 
     
     
         26 . The method of  claim 22 , having further computer executable instructions for performing the step of providing a location of the imperfection on the structure. 
     
     
         27 . The method of  claim 22 , having further computer executable instructions for performing the step of providing a visible indication of the location of the imperfection. 
     
     
         28 . An apparatus for inspecting a composite structure formed from one or more composite tows by an automated fiber placement machine, the apparatus comprising, a composite comparison device (CCD), for comparing a visual image of at least a portion of the composite structure to a virtual image of the at least a portion of the composite structure. 
     
     
         29 . The apparatus of  claim 28 , further comprising, a vision capture element, for taking a visual image of a ply profile in the at least a portion of the composite structure, in real-time, on-the-fly, as the ply is laid down by the automated fiber placement machine, and for providing the visual image to the CCD. 
     
     
         30 . The apparatus of  claim 28 , further comprising, a vision capture element, for taking a visual image of a ply profile in the at least a portion of the composite structure, in real-time, on-the-fly, as the ply is laid down by the automated fiber placement machine, and for providing the visual image to the CCD.