Fundation Research On Automatic Generation Technology Based On STEP-NC Application Referance Model Files

STEP (ISO14649) expends STEP standards into the area of CNC and redefinition the data interface between CNC and CAX and integrates the data information of product design and manufacturing well. It eliminates post processor system of CAM and realizes the seamless bir-directional information stream between CAM system and CNC. It makes information exchanging and sharing among systems conveniently. According to STEP TOOL's forecast, STEP will become the ultimate standard of NC technology gradually in the next decade.On the base of studying priceples of STEP system, aiming at specific CAD file, "STEP-NC program generator V1.0" is invented, which intends to use software method in the program level to realize automatic extraction of features, and generate STEP-NC source code eventually.Based on MFC Dialog form of Visual C++ 6.0 and utilitiying object-oriented thinking of software and MFC software resource,the Program generator V1.0 is established to realize anticipated function of program system. The system has two functional modules mainly. The the first module is a feature extraction which uses DXF drawing exchanging files to develop secondary to extract features of CAD file based on STEP-NC feature and generates corresponding ENTITY EXPRESS statement. The second functional module is about automatic generation of source code of ISO 14649. under Visual C++6.0 developing envirionment,generaing corresponding resoure of part feature from a part feature EXPRESS statement and generating complete ISO14649 source code.Papers focuses on STEP architecture features, modeling language EXPRESS, data-model and constructs core database which can express information well. And mapping from formal description of the C++ language to EXPRESS language is established, doing the necessary basic research for "STEP-NC Programe Generator V1.0" further researching and developing work.