Tertiary Features: An Enhancement of the Definition of Features ina Feature Based Modeler

摘要

For the effective integration of the product development process, a part data representation that is amenable to bothrnCAD and CAM and facilitates process planning has to be developed. The explicit representation of manufacturingrninformation is necessary for computer aided process planning and effective analysis of the part. The informationrnthat is currently available CAD systems is features and geometrical entities such as vertices lines edges and surfacesrnand the topological relationships between the entities. However, the available features are restricted to primary andrnsecondary features such as slot holes etc. Most of the processing information needed, such as heat treatment,rncoating, cleaning, and finishing chamfering etc; are not represented as features but notes. This prevents therndevelopment of a fully automated computer aided processing planning system. There is a need for representingrninformation as codes in a data structure. The biggest advantage of information being stored this way is thernaccessibility and ability to use the data for calculations and for generating process plans. This paper describes thernsemantics for the proper and easy representation of the tertiary features such as heat treatment, coatings, cleaningrnand finishing operations etc. By the representation of this data in a data base form, it will allow the automation ofrnthe process planning function to a higher degree.