臺灣博碩士論文加值系統

本文擬以綜合加工中心機作為量測工具，針對曲面發展一套量測軟體。目
標有二，其一、希望能達成曲面量測及組合。其二、對於量測出之網格點
施以曲面領域成長、曲面領域合併之技術，以期資料處理上更具效率。對
於已知形狀曲面量測擬先經三次樣條曲線擬合法，求得法向量後，以MP7
點量測觸發式探頭由法線方向量取物體之尺寸，另外，對於未知形狀曲面
，擬先由Z 方向直接量測物體輪廓，可得一近似之物體輪廓，若精度不夠
理想，經由法線方向再量測一次，即可得相當精確的物體輪廓。在實際量
測過程中，由於曲面局部變化大小不一或尺寸較大等，我們常需將曲面視
實際的情況切為數個曲塊，分別量測。本軟體亦發展交談式程式，利用雙
三次參數曲面片擬合法簡便地組合局部曲面。關於量測出之網格曲面，基
本上，有其先天上的限制存在，如資料量龐大、編修耗時等缺點，這對PC
級電腦著實是一大負荷。在此我們想引進曲面領域成長、合併之技術，利
用高斯曲率與平均曲率之符號決定曲面局部的形狀，再以最小平方和法擬
合局部曲面，將其以方程式表示，以減輕PC的負擔、增進編修之可能性。
最後，將曲面資訊轉換成.dxf圖形交換檔，以利資料在不同CAD/CAM軟體
間的轉換，進而增進變更設計或修改的可能性及方便性。

The object of this study is to develop a free form surface
measurement system which could measure surface profile on
machining center,and use this data to rebuild the graph of the
model. The program is divided into two parts, one is the
execution of measuring process of free form surfaces,the other
is the parameterization of smooth surface. In the measurement
of free form surfaces, the data points of master surface
are collected from the measurement of machining center.
After cubic spline curvefitting,we can get surface normal
vectors of each points. Then MP7 probe is moved to measure
surface points on normal directions. At last, we construct
its 3D geometry. The second part of this paper is
to deal with transformation of mesh surface to parametric
surface.Using the signs of Gauss curvatures and mean curvatures
of each points, smooth surface can be surfacefitted by least
squares method. Then we will reduce the computer memory size.
This software has the fuctions of surface combination and
data communication to other CAD/CAM systems which can be
carried out via .dxf file.