Inspection of aeronautical mechanical parts with a pan-tilt-zoom camera: an approach guided by the computer-aided design model

Abstract

International audienceWe focus on quality control of mechanical parts in aeronautical context using a single pan-tilt-zoom (PTZ) camera and a computer-aided design (CAD) model of the mechanical part. We use the CAD model to create a theoretical image of the element to be checked, which is further matched with the sensed image of the element to be inspected, using a graph theory–based approach. The matching is carried out in two stages. First, the two images are used to create two attributed graphs representing the primitives (ellipses and line segments) in the images. In the second stage, the graphs are matched using a similarity function built from the primitive parameters. The similarity scores of the matching are injected in the edges of a bipartite graph. A best-match-search procedure in the bipartite graph guarantees the uniqueness of the match solution. The method achieves promising performance in tests with synthetic data including missing elements, displaced elements, size changes, and combinations of these cases. The results open good prospects for using the method with realistic data

Automatic Inspection of Aeronautical Mechanical Assemblies by Matching the 3D CAD Model and Real 2D Images

“…Jovancevic et al [ 15 ] show that utilizing CAD model whenever possible is beneficial for their results in the task of exterior aircraft inspection. Viana et al [ 16 ] have presented a CAD-based inspection of mechanical parts by means of comparison between a reference and a test image. The CAD-based matching method compares an image generated from a CAD model with an image acquired with the 2D camera, using primitives extracted from the contours.…”

“…To the best of our knowledge, the existing methods for assembly/CAD conformity check are based on comparison of rendered synthetic images with real images [ 16 , 17 ]. Those images are further compared in terms of their respective sets of extracted geometrical primitives such as lines and circles/ellipses.…”

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