CAD/CAPP Integration through Object Oriented Feature-based Design

The simplest way to achieve CAD/CAM integration is to generate CNC programs after the completion of the CAD process, while the more rigorous approach in today's integrated manufacturing environment is to prepare the manufacturing process and production plan within the linked design and manufacturing systems. This paper describes the development of an object-oriented feature-based design system for integrating CAD and CAPP. The object-oriented feature-based design system provides an intelligent interface between a CSG based geometric modeller and the process planning functions. The geometric modeller used in this project is the AME (Advanced Modelling Extension) of the commonly used AUTOCAD (Release 11 or above). The concept of feature-object is proposed to express the semantics of integration. Input to the feature-based design system is the Object-Attribute-Value (O-A-V) triplets coding of a workpiece. Based on the AME geometric modeller which is in fact a CSG based solid modeller, the validity of the input geometric features will be ensured. According to the knowledge provided in the rule-based feature mapping system, the design information will be transformed into the appropriate process plan and manufacturing instructions.