This paper presents some research on the use of dense range data for the automatic inspection of mechanical parts that have free-form surfaces. Given a part to be inspected and a corresponding model of the part, the first step towards inspecting the part is the acquisition of a range image of it. In order to be able to compare the part image and its stored model, it is necessary to align the model with the range image of the part. This process, called registration, finds the rigid transformation that superposes model and data. After the registration, the actual inspection uses the range image to verify if all the features predicted in the model are presented and within tolerance. Free-form surfaces are particularly interesting in that few inspection processes can inspect surface shape across the whole surface. We focus on the inspection of free-form surfaces and present some results concerning the extraction of nominal shape models from dense range data using B-splines and the use of B-spline models of free-form surfaces for the purposes of registration.
Edvaldo M. Bispo,
Robert B. Fisher,
"Inspection of free-form surfaces using dense range data", Proc. SPIE 2249, Automated 3D and 2D Vision, (23 November 1994); doi: 10.1117/12.196066; https://doi.org/10.1117/12.196066