A PRODUCT MODELER FOR DISCRETE COMPONENTS

In designing a product, the product specifications are developed first , which conceptually constrains the geometry and functions of the prod uct. Subsequently, its components are designed with the form in mind a nd achieve the functional requirements according to the specifications required. Conventional CAD systems are made for generating the geomet ric form of a part. This is meant to take the place of manual drafting . However, a system such as the one described above is incapable of ca pturing the non-geometric aspects of the designer's intent in a form t hat can be used for automatic process planning. The result is that tol erance, parts relationships, surface finish, etc. cannot be specified by the designer in the CAD environment unless some form of annotation is provided for. Product Modeller (ProMod) provides a concurrent produ ct design environment for designers to assign the product specificatio ns onto the parts' nominal geometry through a spatial relationships en gine. With this information, the detailed design requirements, such as , tolerance and surface finish are generated by a dimension engine and tolerance propagation engine. Based on the functional requirements, t he features of individual part are extracted through a form-function i nterpreter engine, then, they are mapped to the form and function data base to establish manufacturing specifications such as machines and to ols selection. Design evaluator evaluates the machinability and assemb lability of features in accordance with the design rules, machine capa bility and geometric interference. Design advisor provides a way of in corporating modifications to improve the design. Design simulation uni t formulates the problems which come from prototype design experiments and they are submitted to a design evaluator for further evaluation. When the iterative design procedures have been completed, the informat ion, topology model, geometry model, dimension and tolerance model, fo rm-function model, form-feature model, etc. are then created for gener ating the process planning.