基于坐标法的复杂曲面轮廓度的误差评定

复杂曲面的面轮廓度是一个应用广泛而又难于测量和评定的问题.在面轮廓度误差评定过程中,首先将复杂曲面的理论模型离散化后用双三次样条函数进行精确描述,并用该拟合曲面作为误差评定的依据;其次对测量后所得的测头球心位置曲面进行等距平移以得到实测轮廓曲面;最后再采用坐标轮换法求取实测点在以双三次样条函数所表示的理论轮廓上的对应点,从而实现对复杂曲面轮廓度的评定.由于本文用双三次样条函数所表示的曲面作为复杂曲面的一般表示,因此该评定算法可实现测量及评定软件的通用性,并通过计算机仿真,证明该算法的正确性与可行性.

Evaluation of Profile Error of Complex Surface by Coordinate Method

Profile error of complex surface was common and difficult to be measured and evaluated.Firstly,during evaluating surface profile error,the theoretical model of complex surface was dispersed and then was expressed with bi-cubic spline function,so the complex surface was replaced by the fitting surface.Secondly,the actual measured surface was acquired by calculating the isometric surface of the probe center track.Lastly,the coordinate alternation method was used to seed corresponding points of actual measured points on the fitting surface with bi-cubic spline function and finally got the surface profile error.The fitting surface with bi-cubic spline function was the general expression of the random complex surface,so this arithmetic realizes the versatility of the measuring and evaluating program.The validity and feasibility of arithmetic was proved by the computer simulation.