Tool positioning and path generation algorithms for computer-aided manufacturing

CAD/CAM (Computer-Aided Design and Manufacturing) is increasingly being used for part design and for the generation of cutter paths (programs) for numerically controlled (N/C) metal cutting machine tools (mills and lathes). A large number of very interesting algorithms have been developed by the CAD/CAM industry. However, in spite of the obvious importance of the subject, and rich set of open problems, not much academic attention has been given to the development of algorithms for the generation of tool paths. These algorithms provide the foundation for process planning by limiting the types of cutting operations that can be performed automatically on specific geometry. It is therefore necessary for these algorithms to be well understood and robust. With this dissertation we contribute to the establishment of a solid foundation for automatic tool path generation and process planning by presenting a large collection of known and new tool path generation algorithms. They cover the entire spectrum from 2-2${1\over 2}$-axis pocketing to complex 3-5-axis contouring and pocketing on milling machines. Our own original algorithms include a subdivision-based interference-free algorithm for tool positioning on parametric surfaces and curves, a solids-based tool positioning algorithm using fast Boolean intersections, a 2-2${1\over 2}$-axis pocketing algorithm for pockets of general shape with any number of islands, and a new surface-based pocketing and contouring algorithm using tool-dependent planar cuts. In addition to the theoretical correctness and soundness of our algorithms, we have required practical implementation, applicability and efficiency, in the context of the contemporary computing resources. (Copies available exclusively from Micrographics Department, Doheny Library, USC, Los Angeles, CA 90089-0182.)