Application Of Surface Simplification Based On Segmentation In CAD System For Automobile Panel Die

The design and manufacture of Die & Mould play an important role in the development of an automobile. With the widespread application of CAD technology in the mold industry, in the process of design, the processing of surface works as very great proportion in the Die & Mould design, specially the surface simplifying and offsetting applies in the Die & Mould design widely, and it is one of core contents of automobile Die & Mould CAD system. At present when carries on 3D design of Die & Mould, through massive interactive graphs processing, carries on the Die & Mould structural design, if use a complex surface cut out or do some other operations, it is easy to lead to massive data quantity of the final part, and the inconvenient operation at the same time. It has vital significance to use the surface reconstruction to realizes the surface simplification which guarantee certain precision in the automobile Die & Mould CAD system.Through analysis the existing surface simplification principle and the design method of the system, the author proposed the surface simplification method based on grid division. The main work of this article includes: proposed two scatter algorithms based on the NURBS surface, to scatter the surface to disorder set of points, then bases on the thought of point cloud slice in reverse engineering, carries on the grid division of scattered point set, and through the establishment of the distance weighting model of spot, makes up the vacancy of the spot, obtained the standardized set of points which have the topology structure of line and arrange directions. As for the fitted line and arrange curves the author proposed a fairness algorithm which combines the point select method and the energy method to smooth the line and arrange curve. Finally the author analyzed the method bases on the data piecemeal and the boundary recognition, in view of the shape characteristic of components, proposed and realized the way of surface segmentation and the processing of the face around punch profile.