同步移相干涉测试算法的研究

发布时间：2019-04-25 12:09

【摘要】：同步移相干涉测试技术通过采集同一时刻不同空间位置处具有一定相位差的多幅干涉图,能有效避免环境振动带来的影响,是目前抗振效果最好的干涉测量手段。其中斐索型同步移相干涉仪因其共光路的光学结构,大大提高了测量精度和应用范围。研究了一种基于四分之一波片的新型斐索型同步移相干涉原理和技术方法,采用四分之一波片作为参考镜,得到一对正交偏振光,通过偏振光干涉,可同一时刻获得相位依次相差π/2的四幅干涉图,从而消除了振动对干涉测量的影响。研究了干涉图像的位置配准方法,设计实现了两种干涉图位置配准算法:基于Hough变换的圆检测方法以及相位相关方法。前者以圆域干涉背景图为对象,通过域值分割、Canny边缘检测算子获得干涉背景图的轮廓,最后由Hough变换拟合出圆斑方程,以四幅干涉背景图的圆心坐标作为配准依据;后者同样以干涉背景图为对象,运用相位相关算法计算出四幅干涉背景图的相对平移量,以此作为配准依据。两种算法均通过实验验证其可靠性和精确性。研究了相位解包算法,设计实现了基于可靠度排序的解包算法,将实验结果与ZYGO干涉仪的测量结果对比,得到面形误差的PV值为0.004λ,RMS值为0.001λ,验证了算法的准确性;提出了改进的基于全变分最小去噪的路径无关解包算法,实验结果表明,对残差相位去噪后得到解包相位的PV值、RMS值误差优于未去噪的情况。
[Abstract]:Synchronous phase-shifted interferometry is the best interferometric method to avoid the influence of environmental vibration by collecting multiple interferograms with certain phase difference at different spatial positions at the same time. Because of the optical structure of the common optical path, the measurement precision and application range of the Fesso-type synchronous phase-shifting interferometer are greatly improved. In this paper, a new synchronous phase-shifted interference method based on 1/4 wave plate is studied. Using 1/4 wave plate as a reference mirror, a pair of orthogonal polarized light is obtained and interfered by polarized light. Four interferograms with 蟺 / 2 phase difference are obtained at the same time, thus the influence of vibration on interferometry is eliminated. The position registration method of interferogram is studied. Two kinds of interferogram registration algorithms are designed and implemented: circle detection method based on Hough transform and phase correlation method. In the former, the contour of the interference background image is obtained by domain value segmentation and Canny edge detection operator. Finally, the circular spot equation is fitted by the Hough transform, and the center coordinates of the four interferometric background images are used as the registration basis. The latter also takes the interference background image as the object, and calculates the relative translation amount of the four interference background images by using the phase correlation algorithm, which is used as the registration basis. The reliability and accuracy of the two algorithms are verified by experiments. The phase unwrapping algorithm is studied, and the unwrapping algorithm based on reliability ranking is designed and implemented. Comparing the experimental results with the measurement results of ZYGO interferometer, the PV value of surface shape error is 0.004 位 and the RMS value is 0.001 位, which validates the accuracy of the algorithm. An improved path independent unwrapping algorithm based on total variational minimum de-noising is proposed. The experimental results show that the error of RMS value is better than that of non-de-noising when the PV value of the de-noising phase is obtained after residual phase de-noising.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O436.1

【参考文献】