Quality Assured Aircraft Fuselage Production: Data Evaluation of a Quality Control Sensor for Thermoplastic Automated Fiber Placement

In-situ thermoplastic automated fiber placement (TP-AFP) is a lean additive manufacturing process without further vacuum bagging and autoclave cycling. Heated by laser and subsequently compacted with a consolidation roller, the tapes are consolidated on the fly. This makes TP-AFP a single stage manufacturing process. For this highly transient process inline quality assurance (QA) is vital. The inline QA sensor is situated about 100 mm behind the consolidation roller and measures height profiles via laser triangulation. The evaluation routine identifies gaps and overlaps between tows and tracks as well as early/late cut at the beginning and end of each track. Processing the profile data includes outlier removal, thresholding, bitwise operations, the Sobel operator, erode and dilate operations and contour finding. We present the data evaluation of a full-scale fuselage skin of a test shell which was produced with a multitow laying head that processes three ½” carbon fiber tapes. The primary focus is the detection of gaps and overlaps. A 3D spatial plot will give an overview where the production process has to be revised.