<title>Three-dimensional inspection of sculptured surfaces using nonuniform sampling and view planning</title>

Abstract

Indirect adaptive sampling techniques are introduced specifically for 3D inspection of sculptured surfaces (free form) normally found on objects produced by extrusion, die casting, and molding processes. The techniques successfully extends optimum 2D sampling methods to 3D applications. The modified 2-D adaptive sampling techniques are used sequentially twice. First, the critical cross sections are optimally selected, then each section is itself optimally sampled to develop an accurate description using a small number of sampling points. Optimizing view planning achieves the goal of minimum occlusion and minimum rotation to insure complete inspection of an object, and not only satisfies the goal of view planning, but also automatically maximizes the number of surfaces to which adaptive sampling can most fully be applied. The best view based on the number of visible faces and the face area has proven applicable to integrating the finite element (FEM) centroid sampling and indirect adaptive sampling techniques respectively, for the inspection of sculptured surface products. Experimental work has verified that the best view based on the number of visible faces not only maximizes the number of visible meshes for centroid sampling, but also reveals the maximum amount of high curvature regions of an object.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.