Research And Development On The CAM Module Of The Intergrated Reverse Engineering System

Reverse engineering in the manufacturing field is a process that people first measure an exit object model or part and obtain its data, then reconstruct a CAD model of the object or part, and reproduce the object or part through manufacturing in process at last. The relative technology of reverse engineering play an important role in advanced manufacturing technology. The CAM moduel is pivotal in the integrated reverse engineering CAD/CAM system, and its main fuctions are making an appropriate machining project , computing the cutter location, and running the gouge check and post processing , and outputing the G-code at last based on the surface machining information , tools parameters, manufacturing parameters and numerical control machine file. The research and development on the CAM moduel have great theroic meaning and engineering application value in the integrated reverse engineering CAD/CAM system.At present there are two methods in CAM module: one is creating the cutter location upon digital data directly and it is used widely for complex sculptured surface in reverse engineering; the second is at first surface reconstruction, then programming NC cutter location. On a whole analysis of the fuction model and information integration model of the CAM model, the paper presents a technique project that reconstruct the freeform surface mathematics model using NURBS parametric surface and realize the CAM fuction in Pro/NC through Pro/Toolkit,based on which creates a CAM module which is an organic part of the integrated reverse engineering CAD/CAM system and own the ability of automatic dispostion. The research and development practice proves the project is advanced, and is feasible and applicable.The theoretic and development pursuit of this paper including the following items.1. The reconstruction of part mathematics model upon measuring points is pivotal in the reverse engineering. On the contrastive analysises of reconstruction methods, this paper points out the integrated reveser engineering CAD/CAM system should adopt the NRUBS method. The paper researches the mathematics methods of surface reconstruction and numeric control maching based on NRUBS method.2. Using application development tool Pro/Toolkit provided by Pro/ENGINEER, this paper creates a sufrace-milling NC programming organ which encapsulates the surface-milling numeric control maching in Pro/NC. And this paper first brings the Dynamic-Link Library theory and the Open Database Connectivity theory into the system, and creates an interface for the thecnic database and the Pro/ENGINEER system that connect the thecnic database and the CAM module, which makes it possible that the CAM module get the maching parameters from the thecnic database and completes the automatic generation of numerical control program for the freeform surface.3. Five fuctional parts ensured the CAM module of integrated reverse engineering system work properly: thecnic database management, numerical control maching thecnic information transaction, surface-milling NC programming organ, maching simulation and post processing. The module works simply with few intervene and has powerful ability of automatic disposal, and connectes the integrated reverse engineering CAD/CAM system successfully.