Interpretation of CAD models for an automatic machine programming planner

A generalized approach to fast interpretation of objects and their features has so far eluded researchers. In manufacturing, this interpretation can be approached from a vision point of view or from a CAD data perspective. Presently, CAD systems are widely used in several aspects of manufacturing, and such systems will eventually be data driven. It is therefore more efficient to use CAD data for object reasoning in manufacturing. Components can be modelled on a CAD system using various modeling techniques. The method of representation of their geometric information however differs from one CAD system to another. The advent of Initial Graphics Exchange Specification (IGES) now makes it possible to represent CAD data in a neutral and standard manner. This research concentrates on developing an object interpretation system. This interpretation system contains an automatic form feature extractor and a product modeller which acquired the technological information, such as tolerances (including position and form tolerances) and surface finish through users\u27 interface. This research describes a scheme for recognizing and representing features from any CAD system using a neutral graphics data interface. The scheme developed is based on Graph-based feature representation, where features are represented by a set of faces as well as their topological adjacency. Based on theories related to group and graph theory, the strategies for classifying and representing features and methods of decomposing a complicated feature into several simpler features for recognition purposes has been developed. Finally, this work concentrates on ideas related to developing a product modeller. This modeller assists the interpretation of features by providing non-geometric information obtained through the designer. Such information can not be obtained directly from current CAD systems but are nevertheless important in the final attainment of the integration of design and manufacturing systems