Geometric Reasoning Tools for Assembly-oriented CAD

The design process supported by present CAD tools tends to be component oriented rather than dealing with a product as a whole. Furthermore, design evaluation tools often need complete product descriptions to give meaningful results. Presented here is a brief exposition of the architecture and capabilities of an Assembly-oriented Design environment that is currently being developed. It will allow designers to consider assembly issues at a point in the design process where they still have some freedom of action. In describing the Assembly-oriented Design environment, particular emphasis is given to the modelling and geometric reasoning capabilities necessary to support the applications within it. In particular an algorithm for detection of symmetry and primary axes is described. It is based on matching geometric properties of edge-loops within a b-rep solid model and has the advantage of being able to detect partial symmetry.