Research On The Key Thchnologies Of Intelligent CAPP System

Intelligence and integration are main developing directions of CAPP system. Process decision based on the artificial intelligence technology is the key technology of intelligent CAPP system. The paper mainly studys how the computational intelligence in artificial intelligence is applied in decision for machining schemes of featurs, selection for locating datum and optimization of process route.First, the architecture of intelligent CAPP system is designed, in which multiple knowledge bases based on multiple artificial intelligence technologies are co-working, and in order to achieve information linkage between knowledge and CAPP system, users, we use the inner and outer knowledge bases. The integration between CAD and CAPP is also realized.Based opon the analysis of features and machining schemes of turning parts, the decision model for machining schemes of features is put forward. By BP neural network all possible machining schemes of features can be automatically obtained. Network structure, input/output processing methods, training function and selection for training samples are traversed.Under the analysis of factors which influence selection for locating datum of turning parts, the selection model for locating datum based on BP neural network is established. Network structure, input/output processing methods, training function and selection for training samples are traversed.The optimization model for process route based genetic algorithm is built. In order to describe precedence relation among processing units, constraint matrix is introduced and it is automaticly generated by computers. The general program of constraint adjustment algorithm which make the processing units'sequence validity is developed. Optimization course of process route based genetic algorithm is dicussed, including gene incoding, design for fitness function of chromosome, selection, crossover and mutation and so on.Finally use VC++ to program three process decision models above. The system interface and decision process are shown. A turing part is used to validate them validity and feasibility.