THE IMPLEMENTATION OF A FEATURE-BASED COMPONENT REPRESENTATION FOR CAD-CAM INTEGRATION

Recent research and development has the objective of increasing produc tivity and cost effectiveness by integrating many activities such as d esign, analysis, process planning, assembly planning and production pl anning which encompass the entire manufacturing planning and operation al control aspects of a manufacturing enterprise. It has been recogniz ed that a key to the integration lies in the determination of a repres entation scheme for products that can be interpreted for the various n eeds of these different applications. Geometric (solid) modellers were regarded by many researchers as the appropriate representation, but m ore recently a features approach has been proposed to enhance the capa bilities of solid modellers. This paper introduces ongoing research wh ich is aimed at the development of a feature-based design system for p rocess planning. The system is fully integrated with a conventional bo undary representation (Brep) modeller which enhances its modelling cap abilities in representing, editing and validating features of componen ts. The main aspects of the feature-based design system are described in detail, such as the feature library, feature taxonomy, feature oper ations, feature relationships and tolerances. The generation of a deta iled data model for transmission to manufacturing planning activities is also described and demonstrated by reference to an example componen t. A brief indication is given of our parallel research work in using such models as the basis of process planning and process capability mo delling.