Key Techniques Research On Intelligent And Integrated CAD/CAPP System

CAPP can automate the process planning and also CAPP is a key technology for CIMS, FMS and informationization of manufacturing industry. Because process is planned based on a lot of experience knowledge and the mathematical model is hard to build, there are many problems remains unsolved, CAPP can not meet the need of plants and it has become the bottle neck for CAD CAM integration and CIMS. On the other hand, with the development of manufacturing informationization, intelligent and integrated CAPP has become a developing trend.CAPP matches the design specification with the available manufacturing ability, transfer the design information into manufacturing process, the key problem is the process of design and manufacturing information. This thesis aims at solving some urgent problems, such as the intelligent and integrated CAD/CAPP structure, CAPP and CAD integration, the combination of artificial intelligence and CAPP, knowledge acquisition and utilization.First, the CAD/CAPP structure is designed by considering CAD and the CAPP as a whole, the components and its relations of the structure is presented, also the integration of CAD and CAPP is realized by integrating product model with database, and the multiple knowledge bases collaborating working mode and inference based on blackboard is implemented to meet the requirement of CAPP with multitask, multilevel and multi-knowledge function.CAD and CAPP are integrated by integrating product model into database. Based on the feature modeling and the analysis of design and manufacturing process, a new concept process feature is presented, and the definition, classification and attribute representation are given. With this concept, the EER model and data structure is proposed for part modeling, this model can be used as a tool for connecting part information with manufacturing information to build a unified database to support the integration of CAD/CAPP.Based on this concept, the mapping between features and cutters can be made with the computational intelligence of AI so that we can construct the connection among features, cutters and manufacturing resources, the matching is not only for the cutting tool selection, but also for the construction of unified database. A prototype is developed to validate the model and for supporting the realization of CAD/CAPP structure proposed above.At last, the knowledge acquisition and utilization with ANN technology is presented for modeling such knowledge as with complex data structure which is hard to construct a unified knowledge model. The ANN DB can be built with some ANN knowledge model to support the intelligent inference of CAPP together with other knowledge representation. In addition to this, this thesis also introduces the feature evolution approach to facilitate the inference ability of CAPP.