GEOMETRIC REASONING FOR MACHINING FEATURES USING CONVEX DECOMPOSITION

A convex decomposition called the alternating sum of volumes with partitioning (ASVP) is a hierarchical volumetric representation of solid objects obtained from the boundary information. Form features intrinsic to the shape of solid objects can be recognized using ASVP decomposition. As the form-feature decomposition is compact and faithful to the shape of the object, it includes both positive and negative form-feature components. In the paper, conversion procedures from the form-feature decomposition into features useful for machining applications are described. The decomposition is accomplished by taking the complement of the halfspace abstraction of the positive components using the original faces, and combining this with the parent negative components. The resulting negative-feature decomposition represents the removal volume. Alternative decompositions of the removal volume are also obtained by exploiting the geometric information maintained in the decomposition.