Non-contact techniques based on a vision system for the inspection of composite material components: Analysis of the influence quantities

In this paper two different approaches, based on a vision system, are compared for the inspection of a carbon fibre piece, realized using a tow filament winding process. The defect of interest is the surface void percentage, which can strongly influence the mechanical and functional characteristics of the component. The approaches differ in the method of image processing: the first is based on a colour threshold setting; the second is based on a semantic segmentation algorithm. The comparison between the two techniques allows the identification of the main causes of variability, and the individuation of the advantages and limits of each one, which make them more or less suitable for use, depending on the specific application. The preliminary results show that both methods are promising for in field use, provided that the causes of variability are identified and kept under control.