极大望远镜终端仪器结构变形的实时主动补偿方法研究

项目名称： 极大望远镜终端仪器结构变形的实时主动补偿方法研究

项目编号： No.11503059

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 天文学、地球科学

项目作者： 季杭馨

作者单位： 中国科学院国家天文台南京天文光学技术研究所

项目金额： 22万元

中文摘要： 配置在极大望远镜上的科学仪器随着天文观测需求的不断提高，对仪器设计提出了更加苛刻的要求。终端仪器由于望远镜运动或自身消旋运动受到不同重力向量的作用产生一定的结构变形，而且随着望远镜和终端仪器自身线性尺寸的变大影响更为剧烈。为了消除结构变形的影响，除了需要进行光机结构的优化设计，还需要进行主动的补偿矫正。本项目主要以三十米望远镜（TMT）宽视场光学光谱仪（WFOS）为背景进行基于实时主动补偿方法实现极大望远镜终端仪器结构变形的主动补偿系统研究。通过WFOS光机模型的建立，仿真分析光谱仪各器件的补偿灵敏度，利用实时主动补偿算法控制主动补偿系统实现结构变形的矫正并给出补偿精度。本项目的研究将解决4米级以上望远镜终端仪器由于结构变形引起的仪器稳定性下降的问题，通过该项研究推动中国全面参与或主导一两个TMT 科学仪器的研制打下基础，也为我国自主发展中国的天文大望远镜和科学仪器增强配套能力。

中文关键词： 主动补偿系统；极大望远镜；终端仪器；结构变形

英文摘要： In order to satisfy the extremely demanding requirements for astronomical observation, designers of these terminal instruments, which mounted at Cassegrain or Nasmyth foci of large telescope, must make efforts to concern the stringent design requirements. As a telescope tracks, the instrument is subject to a varying gravity vector, so instrument structure and components within it must suffer from gravitationally induced flexure to some degree. The issue is becoming more critical as the instrument size tends to scale with the telescope diameter. To solve this problem, an optimized structure design is primarily consideration but not enough. Further improvements in performance can be achieved if the instruments have active compensation for any residual flexure. This project aim to research on the Wide Field Optical Spectrograph (WFOS) of Thirty Meter Telescope (TMT) and developed an active compensation system capable of compensating the instrument flexure using an active real-time correction method. The optical-mechanical modeling of WFOS is used to do the simulation and analysis. With the help of optical sensitivity analysis, choosing the suitable optical element as the active compensation component. Finally, we examine the Active Flexure Compensation (AFC) predicted mechanical performance, in terms of accuracy of flexure compensation. Image motion in large instruments is a long-standing problem which has become acute at the scale of 4-m telescope, this project will solve this problem and demonstrate how open-loop active compensation can be successfully applied to the larger telescope. This project will develop related technology to the construction of large instruments for extremely large telescope in China and promote the fully participation in the TMT to constructing one or two scientific instrument.

英文关键词： Active compensation system;Extremely Large Telescope;Terminal Instrument;structure flexure