FREE-FORM SURFACE FITTING 3-D DIGITIZED DATA IN REVERSE ENGINEERING

摘要

Reverse engineering is a method for constructing CAD models of actual parts by digitizing an existing object. This paper describes a strategy for measuring with a non-contact 3-D digitizing system. It also describes techniques for generating computer models from 3-D digitized data. The measuring system developed by the authors uses He-Ne laser light. Parametric curve approximation is obtained by the least-square fitting of B-spline curves. For each measuring line, 3-D digitized data are parameterized, and knots are determined chiefly according to curvatures. Free-form surfaces are produced by Coons patch surfaces of C2 class continuity. Sample results show that the proposed methods are effective for generating free-form surfaces.