外文翻譯--基于細分曲面生成的三軸數(shù)控切削軌跡的研究-數(shù)控設計(存儲版)
【正文】 年 月 日 注： 請將該封面與附件裝訂成冊。 兩類切削可以實現(xiàn)快速自動 計算 。從如此差的 CAD 模型中產(chǎn)生的數(shù)控資料這個嚴重的問題經(jīng)常影響產(chǎn)品的質量。然而，在 CAD／凸輪的領域中，它不是如此多的被運用。 在我們的研究中，我們提議包括二個階段的一個軌跡示意圖粗糙的切割和完成切割。在第 7 段中，切削軌跡工具執(zhí)行和他們的加工結果被示范。 。 － map 模型 Z－ map 模型是一個分離的非參數(shù)的在那一高度的曲面代理的特殊形式。切削層的厚度由工具參數(shù)決定。這些新的位置通過尖銳的補助來彌補他們的界限位置。當有一些點在這些三角形上面，我們找到最高點，計算從最高的點到估計邊緣的距離（ dmax )?？赡? M1 網(wǎng)孔切斷界限曲面，換句話說，那綠色的部份正在切斷紅色的部份。 R 是工具半徑 。 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
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