Application of virtual convex polytope in transforming protrusions for automated process planning

In this paper, a two-tier methodology for the transformation of protrusion design features to manufacturing features is presented. In the first stage of the proposed algorithm, a method is proposed to encapsulate the protrusions with virtual convex polytope and transform them into a set of negative machining volumes. The design feature model is transformed into the intermediate feature model that consists of machining volumes using the concept of generic virtual pocket. In the second stage, called the feature refinement stage, relevant manufacturing information is appended to the negative machining volumes to transform the intermediate feature model into the manufacturing feature model. The proposed methodology can be used in the feature-based design and manufacturing systems to support automated process planning and machining functions. Practical examples and computer implementation in an object-oriented environment are also presented in this paper.