A Constraint-Based CAD System Using User-Defined Features

A constraint-based generic mechanism is proposed for defining and instancing user-defined features, which are managed by constraint based library functions to realize feature-based design paradigm. This mechanism not only speeds up the design process and facilitates the representation of assembly constraints and manufacturing constraints in and among user-defined features in detail design phase, but also lays foundation to binding user-defined features with function elements of product, thus supporting computer-aided conceptual design and establishing integrated product model based on user-defined features. The mechanism is realized on Lonicera, a self-developed CAD/CAM integrated system and a case study of aeroengine rotor design is illustrated.