外文翻譯--基于細(xì)分曲面生成的三軸數(shù)控切削軌跡的研究-數(shù)控設(shè)計(jì)(參考版)
2025-05-17 07:21本頁面
【正文】 附件 2：外文原文 Threeaxis NC Cutter Path Generation for Subdivision Surface Abstract In this paper we propose methodologies and algorithms of NC cutter path generation for subdivision surfaces. We select Loop surface as the subdivision surface. A path plan including rough cut and finishcut is developed based on LoD (Level of Detail) property of the subdivision surface. We generate a coarse mesh that covers the limit surface to implement rough cut. For finishcut we use ballend mills and offset cutter contact positions to generate cutter location. In these two steps we use a Zmap model and a collision detection and correction method is presented for the interferencefree of these two steps. We implement our methods and present machining results. All of these two kinds of cutter paths are puted rapidly and automatically. 1. Introduction Machining free form surfaces plays an important role in producing dies and moulds. These freeform surface models are represented with parametric surface patches, . Bspline surfaces and NURBS surfaces, which are generated by CAD (Computer Aided Design) systems [2][6][7]. On the other hand it is difficult to obtain perfect modeling data using these parametric surfaces. For example, constructing a surface model with multipatches can cause gaps especially when the model is plex. A trimming operation among the patches is prone to connectivity errors. Current CAD systems cannot solve these problems automatically, and engineers have to correct them manually. It is a serious problem that NC data generated from such bad CAD models often affects the quality of products. In this research we adopt subdivision surface modeling technologies to solve these problems. The basic concept of the subdivision surface is to generate a smooth surface by repeatedly subdividing an initial polyhedron such as a triangular mesh. It has such a nice property that it can represent a plex shape in only “single” patch. Thus it is seldom required to have a multipatch structure or trimming even for a plex shape. In addition, the subdivision surface has certain continuity, for instance C2continuity almost everywhere on the surface. For these characteristics the subdivision surface has been a major representation in the field of puter animation [3]. However, in the field of CAD/CAM, it has not been used so much. One reason is that we have not yet known if subdivision surface can be applied to CAM. It is our fundamental motivation behind this research. The objective of this research is to develop an effective NC path generation method for subdivision surfaces, and get the best performance of automation and rapidity. In this research we select Loop subdivision surface [1] as our target subdivision surface. Its domain is a triangular mesh. In section 2 we intro
畢業(yè)設(shè)計(jì)相關(guān)推薦
鄂ICP備17016276號-1