Proposed in the thesis are a unified CAM system architecture and new methods for cutting simulation and NC-code verification which form an essential part of a unified CAM system.
The proposed CAM system architecture is has been developed for the manufacturing of dies and molds and is named a unified architecture because it is designed to 1) accommodate diverse types of geometric input data and 2) handle all the major functions of various types of CAM system in a unified fashion. The types of input data that can be handled by the proposed CAM system include CAD data (from commercial CAD systems), digitized data (from coordinate measuring machines or laser scanners), and NC data (from other CAM systems). The CAM functions under the proposed architecture include a) verification of NC codes via cutting simulation, b) generation of gouge-free NC codes, c) accommodation of feedback and feedforward information, d) CAPP (computer automated process planning), e) support of the virtual machining concept.
The main part of the thesis is devoted to a new approach to the non-parametric modeling of cutter swept surfaces (CSS). Instead of explicitly modeling cutter swept volumes, the silhouette curves of the cutter surface are utilized in computing the z-value of the CSS at a grid point. The proposed method is more efficient than the existing methods in computing the z-values of CSS for conventional cutters (i.e., ball-end mills and flat-end mills), and more importantly, it enables the non-parametric modeling of the CSS for a general type of cutters (e.g., APT cutters) which was not possible with the existing methods.
The latter is a major contribution to the cutting simulation technology because computing the z-value of the CSS constitutes the integral part of 3-axis cutting simulation.
The proposed method is also applicable to the non-parametric modeling of tool holders and chucks which is essential for collision detection. Finally, new methods for verifying the results of cutting simulation are described.
