Ray-tracing techniques applied to the accessibility analysis for the automatic contact and non contact inspection

Abstract

Accessibility analysis represents one of the most critical tasks in inspection planning. The aim of this analysis is to determine the valid orientations of the inspection devices used in probe operations and non-contact scanning operations on a Coordinate Measuring Machine (CMM). A STL model has been used for dis-cretizing the inspection part in a set of triangles, which permits the application of the developed system to any type of part, regardless of its shape and complexity. The methodology is based on the application of computer graphics techniques such as ray-tracing, spatial subdivision and back-face culling. This analysis will take into account the real shape and geometry of the inspection device and the constraints imposed by the CMM on which it is mounted. A simplified model has been developed for each inspection device component using different basic geometrical shapes. Finally, collision-free orientations are clustered for minimizing the orientation changes during the inspection process. © 2009 Springer Netherlands.