Step-nc Program Converter

STEP-NC is an extension of STEP into NC machining domain. With the help of the data model provided by STEP, STEP-NC enables seamlessly connection among CAD/CAM/CNC. To implement STEP-NC, some key technology problems should be first solved, such as information extraction, manufacturing feature recognition, adding process information, generating STEP AP238 file, etc. Based on STEP-NC program structure, entity id and attribute, the paper proposes a method of information extraction. According to the definition of manufacturing feature in ISO 14649, makes research into manufacturing feature recognition on typical features.In the last half a century, G code based on ISO 6983 has been widely used. So, though STEP-NC has some advantages in exerting the intelligence of CNC, it is impossible to completely replace G code in short period of time. This paper applies the Catch-CNC platform, from the point of view of practical application, does some exploratory research into the way converting from STEP-NC to Catch-CNC codes.The paper applies object-oriented and program-structure-oriented technology roadmap and method. Firstly the background and meaning of the subject research, and the current research situation both at home and abroad are presented. Secondly the traditional NC programming method Standard ISO 6983, used in Catch-CNC, is researched. Thirdly the fundamental principles and the architecture of STEP and STEP-NC standard and the formalized modeling language EXPRESS are researched. The inheritance relationship between STEP-NC and STEP, differences and similarities between STEP-NC and Catch-CNC are also analyzed. Then deep research is done into the data model and the program structure of STEP-NC. A method of converting from STEP-NC to Catch-CNC codes is proposed, including information extraction from the STEP-NC program, recognition method of some typical manufacturing feature, genaration principle of tool path and method converting to G/M codes. In the last, the method is tested and verified by an example, and it achieves expected results.The paper proposes a way to convert STEP-NC program to G/M codes, with this method some easy G/M codes can be generated, and by this way some exploratory research is made into the STEP-NC.