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(shè)計(完整版)
【正文】 of discrete nonparametric surface representation in which the heights at the grid points are stored in a twodimensional array, as depicted in Fig . It has been widely used in NC cutter path generation [2]. The grid is determined by and , where is the reference point and We first convert the subdivision surface to Zmap model in order to generate an NC cutter path. In this Zmap sampling process, for each grid point we sample its zvalue by intersecting the line from the grid point along zdirection with the surface. After the Zmap sampling, we generate a cutter path by traversing each x (or y)constant grid line so that the cutter contacts with the Zmap surface. 4. Rough cut path generation Basically in order to remove large amount of volume we cut a workpiece layer by layer with flatend mill, which was called slicecut and also adopted in other previous research [10]. The slicecut is done along a roughcut surface. Its thickness of a cuttinglayer can be decided by the tool parameters. The roughcut surface should enclose the subdivision surface with a certain amount of gap (cutting allowance) and should be as simple as possible for fast putation. A straightforward insight is to use an intermediate coarse mesh as the roughcut surface. However, this rough mesh does not always satisfy condition for no overcut. So we convert it to a mesh, which approximately satisfies these conditions. We call it a cover mesh. . Cover mesh generation Fig shows our basic idea for generating a cover mesh for a rough mesh illustrated in the two dimensional case. We move those vertices under the surface above the surface as shown in the lower part of the figure in order to overe the overcut problem. These new positions are given by offsetting their limit positions by the cutting allowance. In this way it seems that we can generate a cover mesh that always lies above the surface. However the situation in the three dimensional space is not so easy. Some part of the limit surface may e above the mesh even though all the vertices are above the surface. Such a part can be detected by checking the local convex hull of the control mesh. In order to solve this problem we used Jos Stam39。在產(chǎn)生覆蓋網(wǎng)孔的 Z－ map 模型之后，我們在垂直于 Z 方向上把它一層一層的切成薄片。在圖 (f）中，紅色界限曲面不切斷藍色覆蓋網(wǎng)孔。在邊界上，我們不能夠估算邊緣曲線上的點，除了δ被 增加。 圖 二維覆蓋網(wǎng)孔 然而，三維空間的情形并不是如此的容易。簡單的洞察力是由于粗切削曲面而使用一中間的粗糙網(wǎng)孔。格子 是以 和 而定， 是參考點， ?是格網(wǎng)間距。同時新的頂點進入邊緣之內(nèi)是被稱為奇數(shù)頂點。 在這一個段中，我們簡要地介紹環(huán)狀細分曲面。換句話說，使用粗糙的網(wǎng)孔作為粗糙切割和好的網(wǎng)孔來完成切割。這是在這項研究后的基本原則。細分曲面的基本觀念是產(chǎn)生一個平滑曲面通過重 復(fù)地細分一個最初的多面體。這些自由形態(tài)曲面模型被曲現(xiàn)為參數(shù)曲面小 塊。 我們選擇環(huán)狀曲面的細分曲面。 附件 1：外文資料翻譯譯文 基于細分曲面生成的三軸數(shù)控切削軌跡的研究 摘要 在本文中，我們提出數(shù)控切削軌跡生成細分曲面的方法和算法。 機械加工自由形態(tài)曲面在生產(chǎn)模具方面占據(jù)一個重要的角色。在這研究中，我們采用細分曲面模型工藝來解決這些問題。一個原因是我們?nèi)匀徊恢朗欠窦毞智孢m用于凸輪。這個方法的開發(fā) LoD 細分曲面的性能為了這二個階段。最后一段我們得出最后的結(jié)論。在這些操作中舊的頂點 （甚至被稱為頂點）被移動到新的位置。在格子
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