DESIGN OF OBJECT-ORIENTED DATABASE FOR THE DEFINITION OF MACHINING OPERATION SEQUENCES OF 3D WORKPIECES

This paper describes the activities of Object-Oriented (OO) analysis t hat were implemented in order to obtain a high part representation lev el and to give sets of structured and hierarchical data to the Compute r Aided Process Planning (CAPP) system. The OO modeling activities wer e carried out by using the Object-Oriented System Analysis (OOSA) meth od which allows careful specification of all the information contained inside the system. All the models used by this method have been descr ibed in detail to show how the OO database is defined and how it can b e used by a generative CAPP system. The feature model proposed is defi ned by taking all the part information that;can be recognized and extr acted from the Computer Aided Design (CAD) model into account. The res ult is the design of an OO database which allows the CAPP system to us e manufacturing features to define machining operation sequences of 3D workpieces. The approach proposed is generic enough to integrate any geometrical forms which can be recognized and identified from the CAD system. Hole geometry is taken as an example to show the link between the step of OO analysis and the step of knowledge representation in th e Expert System which has been used to generate machining cycles. The OO database presented makes up a real solution of CAD/CAPP/CAM integra tion by using feature modeling. (C) 1998 Elsevier Science Ltd. All rig hts reserved.