For Virtual Assembly Design Information Parsing Algorithm Research

Construction the Object Model of parts the base of the virtual assembly system. The current virtual assembly environment mainly uses VRML language to describe object parts models. However, the VRML language can only describe objects in the triangle- patch, which causes the loss of a lot of design information, and fails to meet the demand for virtual assembly of complex products. Through extracting from STEP files parts of design information, it can be achieved the transformation from Design environment to virtual assembly system, to meet the demand for parts model.This paper focuses on the analysis and extraction of parts feature information in STEP documents. An in-depth study of the STEP information model is conducted and the analytical algorithm of parts design information is proposed, i. e., to identify and extract parts geometrical and topological information from standard STEP documents, and then analyze parts feature information to provide data support for virtual assembly system. It attempts to design a widely applicable analytical algorithm for complex parts feature combinations, which also realizes the extraction of a number of key feature parameters in the current analytical system.Through the construction of Prototype System, this paper achieves the above-mentioned method, which realizes the whole process like lexical analysis,syntax analysis,semantic analysis and generate the XML file. The analytical system achieve the common feature such as cuboid,Cylindrical type(cylinder,through-hole,blind-hole,round-fillet),slot type(slot,dovetail-slot),sphere,cone of automatic identification and extraction of parameters, application complex parts to resolve the various features mentioned above.