Research And Application Of Feature Recognition Technology In3D-CAPP System

Process design is the bridge between product design and manufacturing, the CAPP system based on3D-model, which has great significant to improve the level of product research, is the important means to realize the quantification and intelligent of the process design. Along with the development of computer, the technical theory of the characteristics in CAPP has showed its unique advantage, which has promoted the development of3D-CAPP. This thesis combines the requirement of the3D-CAPP system, uses the feature recognition method based on body decomposition and combination, discusses how to describe,store, match and extract the feature information, then achieves the exchange and sharing of the data during the integration of CAD/CAPP. The mainly research work of this thesis is as follows:(1) The existed methods and problems of feature recognition technology were analyzed; directed to the demand of CAPP system during the integration, the feature recognition method based on body decomposition and combination were put forward, at the same time, were applied into the development of3D-CAPP system, and then a system architecture were constructed based on this method.(2) Based on the general description method of part feature information, a method based on adjacency graph had been proposed and then performed some extension. The thesis researched the method about how to store the information of the part, and used the expanded attribute adjacency matrix to store the part's figure structure, used the extended attribute information table to store the other information. Also introduced various process models appearing in the feature recognition method, and used the above method to store their information, which facilitated to the subsequent operations.(3) Some typical unit dela-volumes and their adjacency matrix in feature recognition technology were researched, also, the feature information matching method was formulated based on these typical adjacency matrixes, and then the recognition of dela-volume could been finished. The extraction method of characteristics information in3D-CAPP system was introduced, respectively about the SolidWorks files and STEP files. The rebuilding method about process model during the3D process design was researched, which had used the feature recognition technology. (4) Based on the3D-CAPP system structure which been build above,many related development work was started, a example was used to illustrate the application situation of the feature recognition technology in3D-CAPP system.This thesis mainly researches the feature recognition method based on body decomposition and combination, applies it into the3D-CAPP system. It is not only helpful to enhance the intelligence of process feature recognition, but also provides an effective way to integrate CAD/CAPP, with certain theory significance and practice application values.