Research On Combined Surface Reconstruction Technology And NC Machining Experiments

Surface reconstruction is the key technology of reverse engineering,during the process of surface reconstruction characteristics of the reconstructed surface and high precision should be guaranteed.The research of surface reconstruction based on different data formats has been a hot issue in the field of mechanical manufacturing.To this end,the research on surface reconstruction of reserving features of shoe last data based on IGES format has been done in this paper.Contributions of this paper include following aspects:The surface intersection algorithm is used to slice the combined surface of IGES format,and the slice data is obtained for the surface reconstruction.IGES reading and writing engine is designed to accomplish triangulation of boundary surface and covert triangulate data into standard STL format by extracting compound surface features,discretizing features of boundary surface in the file and matching side line of adjacent boundary surfaces.STL format files of shoe last have been sliced and the features of combined surface have been extracted and smoothed based on slicing data points,and series of offset curves are generated.The whole section point cloud are obtained after the process of slicing the extended parts,and then B-spline curve interpolation are done on combined surface.The cuspidal points in each slicing are obtained based on curvature and parameters of slicing curve which retained cuspidal features are calculated in this paper.Surface mesh data points are obtained by using B-spline method,and curve data parameter optimization method was proposed considering the smoothness of the surface to completing reconstruction of combined surface for the leaflets on B-spline surfaces.Re-development of software module based on C++ language is done to complete format conversion between IGES and STL,extension based on slicing data points,retention characteristics of surface reconstruction and basic view transformation based on mouse,and then the above algorithm are embedded in CAM software system.At last,the NC machining method of shoe last is studied,and to verify the effectiveness of surface reconstruction,the NC machining experiment is done with the five axis shoe last NC machine.