Reverse Engineering Of DMIS-based Automatic Measurement Of Key Technology Research And Implementation

CAD model reconstruction is a key technology in reverse engineering, it involves computer, image processing, graphics, neural network, computational geometry, measure technologies, numerical control and other sciences and becomes actually one of research and applying focuses in academic circle, especially in CAD/CAM domain. Automatic measuring and modeling for the parts with complex free surfaces, is a very important technology of reverse engineering CAD modeling and system developing. This research has a broad application value, especially in aviation, aerospace and automobile industry. Aiming at using CMM to measure parts with complex free surface and integrating NPU-SRMS (NPU-Surface Remodeling System), this thesis mainly performs the research in the key technologies of automatic measuring in CAD model reconstruction process. The completed main research work in this thesis includes: investigating the Dimensional Measuring Interface Specification, involving its application environment, structure, grammar, character definition, tolerance definition, motion definition, measure definition and coordinate; discussing triangle Bezier surface theory, proposed an algorithm of triangle division for scattered points, reviewing the method of defining measure points?number and distribution and putting forward the algorithm of defining measure points for single and whole surface according to need of NPU-SRMS; solving the problem of measuring path, canying out dynamic simulation of path and according to definition in DMIS building up the mapping relation to produce the measuring control files; finally introducing NPU- SRMS, involving it抯 flow chart, software and hardware environment, function modules and application examples.