相位测量轮廓术中三维坐标校准新方法

A New Method of Three-Dimensional Coordinates Calibration in Phase Measuring Profilometry

提出了一种新的用于相位测量轮廓术中的三维坐标校准方法。该方法用一个含有三个虚拟校准平面的标准块代替传统相位测量轮廓术校准方法中使用的标准平面 ,每个虚拟校准平面由多个高度相同但空间离散分布的子区域组成 ,相应的连续相位恢复是通过一个迭代过程实现的 ,同时各个子区域还被用于横向坐标的校准。由于各个虚拟校准平面间高度是垂直变化的 ,传统的相位展开不能得到正确的相对位置关系 ,基于等效波长概念 ,提出了一种准确的虚拟校准平面连续相位间相对位置恢复的办法。此校准方法的特点是 :在校准过程中不需要标准平面的多次精确平移 ;仅需要一次测量就可以完成高度和横向坐标的同时校准。文中给出的实验结果说明了该校准方法的有效性和可行性。

In this method, traditional standard plane in phase\|measuring profilometry (PMP) was replaced by a calibration gauge containing three virtual calibration planes and a reference plane. The application of calibration gauge avoided precise translation of standard plane during calibration procedure. In addition, circular steps were designed to calibrate lateral coordinates automatically. With this calibration gauge, 3D coordinates could be calibrated through only one measurement. To recover the continuous phase distribution of all steps with the same height, an iterative procedure was proposed. Based on the known geometric parameters of calibration gauge and approximate estimation of equivalent wavelength, the fitted phase surfaces of three virtual calibration planes were adjusted to their ideal positions relative to the reference plane. Experiment results showed that this method was suitable for portable measurement systems using PMP.