基于双目视觉的镜面绝对面型测量原理及其应用研究

项目名称： 基于双目视觉的镜面绝对面型测量原理及其应用研究

项目编号： No.11473017

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 天文学、地球科学

项目作者： 何勇

作者单位： 南京理工大学

项目金额： 70万元

中文摘要： 先进天文望远镜中广泛使用的自由曲面镜面具有非旋转对称或高非球面度的特点，难以采用传统检测手段测量面形。相位偏折术是一种通过探测标准条纹经过被测镜面反射后的变形量进行面形检测的技术，因兼具灵活性、测量效率和测量精度，可用于自由曲面的测量。然而传统的条纹反射法需要知道被测件的CAD数据，属于相对检测。为了实现被测面上各点与CAD数据各个点的匹配，需要对测试设备的装调提出严格要求。本课题将以相位偏折术为基础，引入双目视觉的概念，提出基于双目视觉的镜面绝对面形测量方法；设计标定板，提出一种将测试显示屏坐标系和两个探测器各自坐标系统一到被测件所在的世界坐标系中的方法；提出一种多频外差的相位解包算法，实现相位的高精度展开；研究多种基于梯度的面形恢复算法，分析各自算法的利弊。基于以上方案，通过对不同面形镜面的测量研究，完善基于双目视觉的相位偏折术理论与技术，以满足天文光学镜面检测的灵活性、高精度和高效率

中文关键词： 光学检测；天文仪器；自适应光学

英文摘要： The free-form mirrors widely used in the advanced astronomic telescope are usually rotational asymmetrical or highly aspheric, therefore their surface shapes are hard to measure by the traditional methods. The phase measuring deflection (PMD) technology is suitable for the free-form testing due to its flexibility, efficiency and accuracy, which is based on the deformation detection of the reflection image of the standard fringes by the test mirror. The traditional fringe reflection method, however, need to know the CAD data of the object. It belongs to the relative detect. In order to match the point of the measured surfaces and each point of CAD, we need to install the equipment carefully. For this concept, the subject will base on the method of PMD technology and binocular vision technology, raise the method of absolute shape measurement based on binocular vision mirror. Design calibration board, proposed a ways for test the transformation matrix of screen coordinates and two each detector coordinate system with world coordinate system. Propose a multi-frequency heterodyne phase unwrapping algorithms to achieve high-precision phase unwrapped. Research a variety of surface shape recovery gradient-based algorithm to analyze the pros and cons of each algorithm. These theories and techniques of PMD will be studied by measuring different types of mirror, and the demands on the accuracy, efficiency and flexibility in the astronomic optics can be satisfied.

英文关键词： optical testing;absolute specular surface;binocular vision photogram