基于PSD的大口径天线副面位姿测量技术研究

With the rapid development of science and technology, mankind’s quest for the mystery of the universe has received increasingly powerful support of equipment and technics. Large-diameter radio telescopes are much accounted of astronomers for their sensitive angular resolution and powerful capabilities of information gathering and amplification. The accuracy of the primary and subreflectors of the radio telescope and the alignment accuracy of the primary and subreflectors restrict the upper limit of the performance of the telescope. In order to meet the requirements for measuring the subreflector position and attitude of the radio telescope, laser array measurement is proposed to survey the position and orientation of the subreflector, accurately and quickly. Next, we can compensate the variation of the positon and orientation of the subreflector to improve the system antenna gain and aperture efficiency and other performance of the radio.. Based on laser arrays ad PSD detector, this project do research on the high-precision measurement for QTT 110m large-diameter antenna. The main research include precise laser array theoretical research and simulation analysis over long distance, fast and accurate extraction of Laser Spot Gravity utilizing PSD and numerical solution of position and orientation of the subreflector using spot positional relationship. Finally, the environmental impact factors will be analyzed and the database of environment will be established through actual measurement and the environmental compensation model can be introduced, the measurement system can be optimized. As QTT is under construction, and aimed to be the world-class while QTT is proposed, The project will lay a good foundation for the research on the measurement of the position and orientation of the subreflector of QTT in advance. It also provide theoretical basis and engineering experience for the wide application of location and orientation measurement over long-distance.

随着科学技术的迅猛发展，人类对宇宙奥秘探求的渴望得到了愈加有力的设备和技术支撑，大口径射电望远镜以其灵敏的角分辨率、强大的信息汇聚能力受到天文学家的青睐，然而射电望远镜主副面面形以及对准精度制约着望远镜性能的上限。针对射电望远镜副面位姿的测量要求，拟在本研究中通过激光阵列测量技术，对副面位姿完成快速高精度测量，继而对副面位姿进行补偿调整，提升系统天线增益与口面效率等各项性能。.本项目主要基于激光阵列及PSD探测器对大口径天线副面位姿测量展开技术研究。主要研究内容包括长距离下稳定和精准的激光阵列理论研究与仿真分析，激光光斑重心快速准确的提取以及利用光斑位置关系对副面位姿数值求解。最后分析环境影响因素，实测获取环境数据库，引入环境补偿模型优化测量系统。作为在建的世界一流的QTT，本项目将为其副面位姿测量与调整提前做好研究基础，同时也为远距离位姿测量技术的广泛应用提供理论基础与工程经验。

本研究针对在建的中国110米口径天线(QTT)展开，其副反射面口径较大，极易受到外部环境重力、热、风等影响发生姿态变化导致天线系统性能降低，为提高天线工作效率，必须要实现天线副面6自由度位姿高精度动态测量以反馈天线系统及时准确的完成姿态调整。通过研究阵列激光技术，利用DOE分束原理实现激光发射阵列覆盖随副面运动的PSD探测器，且至少三束激光照射在PSD靶面上；然后直接通过PSD提取三个激光光斑质心二维坐标，分析PSD二维点坐标以及激光束关系，建立相交光斑质心三维坐标求解模型；通过建立Bursa模型完成PSD坐标系到天线系统坐标系的转换，获得天线副面姿态的3个自由度平移信息以及3个自由度转动信息，并展开算例仿真，结果显示较为理想。针对已建成的新疆南山的25米天线展开的原理验证实验结果表明，所研究的技术方案在距离5.78m位置可在秒级时间内获得副面6自由度位姿信息，平移测量RMS误差0.014mm、转动RMS误差0.37°，可以满足实时高精度的天线副面姿态信息测量需求。本项目研究过程中主要撰写论文5篇，申请专利3项，并培养学生3名。