| Analyzing the accessibility of a model is important to a variety of applications in automated manufacturing. Practical and robust analysis techniques are developed in this dissertation, applicable to automated tool path generation and machine selection for models bound by complex freeform surfaces. Discrete and multiview visibility analysis methods form the basis of the presented techniques. The machine tool is abstracted as a half-line in contact with the model, extending to infinity in some direction d&ar; . Results are applicable to three-axis milling as well as a new form of five-axis contouring, fulcrum point milling, in which the tool axis is constrained through some fixed point k.;Discrete analysis characterizes the visibility of a surface from a single view point. A discrete analysis technique is developed, applicable to the general hidden region partitioning problem, resulting in the partitioning of a surface into wholly visible and wholly occluded regions. The technique relies on robust contour classification, freeform shadow volume construction, as well as results from singularity theory employed in contour segmentation.;Multiview analysis provides a characterization of visibility over a range of viewpoints. The multiview analysis technique introduced here locates fulcrum points k providing fulcrum point accessibility to a model in its entirety. The technique additionally supports automated machine selection, as well as consideration of tools of a radius and taper angle. All techniques are implemented within the Alpha_1 geometric modeling package with demonstrated results provided. |
