Research And System Implementation Of Complex Surface Segmentation Method For Manufacturing

With the development of high-tech,and the improvement of product design and production automation,the application of complex surfaces has become more and more extensive.Current CAD modeling techniques have been able to design complex surfaces that are aesthetically pleasing and smooth,but the fabrication of these complex surfaces remains challenging.At present,the manufacture of complex surfaces is mainly realized by numerical control machining.Compared with the single-process machining of the entire surface,the numerical control machining based on region segmentation has higher processing efficiency and better processing quality.The key technology of numerical control machining based on region segmentation is the automatic segmentation of complex surface.However,the existing complex surface segmentation method is difficult to be applied in actual engineering production,because the result of the segmentation is either somewhat fragmented or not uniform enough.Therefore,this paper studies the segmentation method of complex surfaces,aiming to divide a complex surface into some machinable regions,which provides a kind of manufacturing method for complex surface models.For the long strip target model,this paper proposes a complex surface segmentation method based on cone spline surface.For a given surface,the algorithm first calculates an initial developable surface to approximate it,which is then segmented into a set of regions by clustering on axis lines of local fitting cones to the developable surface.Shape parameters of conical patches are determined by solving a surface fitting problem with geometric constraints of cones.A precise cone spline surface is constructed by mapping the optimized conical patches to the space of cone spline surfaces.The experimental results demonstrate the capability of the proposed method to convert a surface into a smooth composition of conical patches which facilities the manufacturing of surface models.For non-long strip target models,this paper proposes a complex surface segmentation based on developable surface.For a given surface,the method firstly performs initial region segmentation on the goal model according to the property of the spherical image of the developable surface;Then,by means of shrinkage and expansion,a segmentation region with good expandability is extracted;Following,an approximate developable surface is constructed for each segmentation region;Finally,to obtain the segmentation result that covers the entire model,the segmentation region is expanded and optimized by the growth of the approximate developable surface.The experimental results show that the method can segment a complex surface into some regions with good expandability.Based on the above theoretical research,this paper designs and implements a complex surface segmentation system for manufacturing.The system can segment a long strip target model into a smooth composition of some conical patches,and at the same time can segment a non-long strip target model into some regions with good expandability.The experimental results of the example model verify the effectiveness of the complex surface segmentation system for manufacturing.