Study Of Computer Aided Shafting Design System Based On Knowledge

The thesis discusses how to apply parametric map technique based on KBR(knowledge based reasoning) in CAD system for special fields. Through the technology, intelligence level of CAD system for special fields would be improved obviously.The project is supported by Hi-Tech Research and Development Program of China.In order to have the traditional CAD system had design knowledge in some special fields and the design knowledge can be modified as the different requirements for different users, the system must possess the independent design knowledge base. Generally speaking, knowledge base is constructed by Design Platform for Knowledge Base System. In this thesis, the system modeling, knowledge reasoning mechanism, knowledge collection and expression and knowledge utility of KMKBP, namely Kaimu Design Flatform for Knowledge Base System, are discussed. At the same time, the thesis puts forward that the reasoning machine should separate from knowledge base, and the knowledge base system should be integrated with other application system entirely.For meeting the demand of exploiting design knowledge in knowledge base, the CAD system for special fields should adopt the parametric map technology, with which, the mechanical part is divided into some parametric features. And much shape or position constraint relationship exists between features. The adoption of dragging and dropping technology and intelligent navigation technology makes users can manipulate the system more conveniently. Finally, the maintenance of the feature model is discussed in the thesis.Based on the methodology mentioned above, under the support of Hi-Tech Research and Development Program of China, a CAD system based on knowledge reasoning(SSCAD) has been developed, and the system is integrated with KMCAD 3D system. With the system, a shaft part design scheme can be attainted more effectively.