APPLICATION RESEARCH OF COMBINATION PRINCIPLE IN CAD FEATURE RECOGNIZATION

The method of extracting the basic features of part from the file of STEP AP214 of 3-D model is proposed. All faces in the file are the minimal elements. The combination is done for the faces with geometry restrictions and some attributes by the theory of the best alphabetic tree which is constructed by HU--TUCKER algorithm in combination principle. So the basic features could be attained. This provides the research basis to the more share and integration of CAD information in the virtual enterprises. Finally, a case is used to illustrate the validity of the approach.