环形拼接太阳望远镜主镜控制系统研究

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	环形拼接太阳望远镜主镜控制系统研究
其他题名	Research on Primary Mirror Control System of Segmented Ring Solar Telescope
	郭泰
学位类型	博士
导师	金振宇
	2018-07-01
学位授予单位	中国科学院大学
学位授予地点	北京
学位专业	天文技术与方法
关键词	主动光学拼接镜面环形干涉望远镜太阳望远镜集成建模
摘要	中国巨型太阳望远镜（CGST）是我国建设下一代大型地基太阳望远镜的计划。CGST要在1微米以上波段实现太阳高分辨成像观测，并实现高分辨的太阳大气流场与矢量磁场测量。八米环形太阳望远镜（8m-RST）方案因其偏振交扰小和易实现主焦点热控等优点，成为中国巨型太阳望远镜计划的重要设计方案。8m-RST的主镜是由等腰梯形子镜拼接形成的环形抛物面反射镜。其主镜系统通过约束子镜面内位移和主动调节子镜离面位移来保持面形。不同于全孔径拼接镜面的主动光学控制，环形拼接镜面需附加子镜倾斜量探测才能实现有效的面形保持控制。但已有成果中没有开展子镜面内位移、系统采样频率等关键参数对8m-RST主镜控制系统的影响的研究。文章针对这些问题开展了建模仿真、控制方案改进和试验平台搭建等工作：一、子镜的面内位移会影响边缘传感器与倾斜传感器的读出。建立了8m-RST主镜系统的六自由度仿真平台。分析表明：子镜的面内位移超过50nm时，主镜控制系统无法保持8m-RST的成像所需面形。为此，提出了8m-RST的主镜控制系统的改进方案：在拼缝处增加间隙量与剪切量传感器来估算子镜面内位移和补偿边缘传感器和倾斜传感器读出，两种附加传感器的测量精度应达到26nm。二、系统的采样频率影响控制系统稳定性和控制带宽。建立了8m-RST主镜系统的离散时间仿真模型，得到了系统相对稳定性、控制带宽与采样周期之间的关系。设计了倾斜传感器与边缘传感器异步采样的仿真方法，并引入了风荷载模型。通过分析风扰对8m-RST主镜系统的影响，确定了主镜控制器的基本参数。三、8m-RST主镜控制的研究成果多基于仿真分析，有待实践来推进可行性验证。作者参与搭建了云南天文台拼接镜面（YNOSM）实验平台。并在该平台上开展了主动光学控制的相关实验。论文的第一部分（前三章）是背景介绍；论文的第二部分（第4章到第6章）是针对前述三个问题的主要研究内容；论文最后（第7章）是总结与展望。
其他摘要	Chinese Giant Solar Telescope (CGST) is the next generation of large ground-based solar telescopes of China.CGST is required to observe the high resolution imaging of solar surface at near infrared bands (~ 1 μm), and to detect the fine structure of solar magnetic field and dynamic field. Due to the advantages of ring structure in polarization detection and thermal control, the current design of CGST is an 8 meter Ring Solar Telescope (8m-RST).The primary mirror of 8m-RST is a ring parabolic formed by isosceles trapezoid segments. The primary mirror control system (M1CS) keeps the shape by restricting the in-plane displacement of segments and adjusting the out-of-plane displacement of segments.Different from the active control of the full aperture segmented mirror, the segmented ring mirror requires added tip sensor for active maintaining.However, there is no research on the influence of the key parameters such as the in-plane displacement of segments and the sampling frequency of the control system on M1CS of 8m-RST. This dissertation attends to on modeling, simulation, improving control strategy and building experimental platform.Firstly. The in-plane displacement of segments will affect the reading of edge sensors and tip sensors. This study establishes a 6-dof simulating platform for primary mirror system of 8m-RST. Simulation shows that the M1CS can not maintain the right surface for 8m-RST imaging quality on 50 nm in-plane displacement of segments. For this, the improvement of primary mirror control strategy of 8m-RST is proposed. The gap and shear sensor are added for estimating the in-plane displacement, and then, modifying edge sensor and tilt sensor readings. The measurement accuracy of these two kinds of added sensors should be better than 26 nm.Secondly. The sampling frequency affects the stability and bandwidth of M1CS. In this study, the discrete time simulation model of 8m-RST main mirror system was established, and the relationship between the relative stability of the system, the control bandwidth and the sampling period was obtained.A simulation method for asynchronous sampling of tip sensor and edge sensor is designed.Wind load model is imported to analyze the influence of wind disturbance on 8m-RST primary mirror system.It is obtained that the sampling frequency of tip sensor should be faster than 10 Hertz.Finally. Lots of research results for M1CS of 8m-RST are based on the simulation analysis, which is still to be carried out to advance the feasibility verification. The author participated in the construction of the experimental platform of yunnan observatories segmented mirror (YNOSM), and carried out some active optical experiment based on this platform. The first unit of this dissertation (the first three chapters) is the background introduction.The second unit of it (chapters 4 through 6) is the main studies of three problems above.The last of it (chapter 7) is summary and outlook.
学科领域	天文学 ; 太阳与太阳系 ; 太阳与太阳系其他学科 ; 电子、通信与自动控制技术 ; 自动控制技术
学科门类	理学 ; 理学::天文学 ; 工学 ; 工学::电子科学与技术（可授工学、理学学位） ; 工学:::控制科学与工程
页数	130
语种	中文
文献类型	学位论文
条目标识符	http://ir.ynao.ac.cn/handle/114a53/25410
专题	天文技术实验室
作者单位	中国科学院云南天文台
第一作者单位	中国科学院云南天文台
推荐引用方式 GB/T 7714	郭泰. 环形拼接太阳望远镜主镜控制系统研究[D]. 北京. 中国科学院大学,2018.

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