Boundary extraction algorithm for cutting area detection

Abstract

In sculptured surface machining, many machining operations require cutting areas to be expressed in terms of a boundary representation. To extract cutting areas from a sculptured surface, this paper employs a regular grid model (Z-map model) and presents a procedure extracting areas from a Z-map model. The extracted areas may correspond to various machining features, depending on what the Z-map stores, such as curvature (fillet, uncut area), slope (wall, floor) and Z-values (contour). The core of the procedure is a 'boundary extraction algorithm' extracting boundaries and identifying the inclusion relationships among the boundaries from a binary image. The time complexity of the boundary extraction algorithm is O(n), where n is the number of runs. In terms of its time complexity and simplicity, the proposed algorithm has advantages over the prior ones. Empirical tests show the performance of the proposed algorithm. (C) 2001 Elsevier Science Ltd. All rights reserved.