一米红外太阳望远镜(New Vacuum Solar Telescope论文中简称为NVST)是我国目前非常重要的太阳观测设备，其科学目标是在0.3um～2.5um波段，对太阳流场和磁场进行高分辨率的成像及光谱观测，由此决定了NVST控制系统的开环跟踪精度要达到0.5〞/30s，5〞/10min，光电导行闭环跟踪精度要达到0.3〞，且在四级风作用下望远镜及控制系统能正常工作。本文对NVST控制系统展开了深入、全面的研究，其目标是研究如何实现NVST的跟踪性能和控制系统功能。论文在第二章重点讨论了NVST伺服驱动系统反馈控制结构、数学模型、控制算法、以及速度控制器和位置控制器的抗风干扰设计，数值模拟和实验测试表明望远镜伺服驱动系统能在四级风下正常工作，伺服系统稳态误差RMS值能控制在0.5〞以内。论文第三章主要研究NVST开环跟踪误差问题，从对NVST伺服驱动系统的引导信号和位置反馈信号的误差分析出发，建立了NVST测角系统的误差模型和开环跟踪误差模型，通过对星的跟踪和定位观测，用导星系统记录相应的误差，用数据拟合方法得到NVST测角系统的误差模型和开环跟踪误差模型，并给出了误差模型修正前后的结果对比，表明NVST开环跟踪精度得到较大的提高。第四章研究NVST光电导行闭环，其中如何高精度快速地检测日面像的移动是本章的核心，在对比日面像的几种检测方法后，重点讨论了二维修正矩在NVST光电导行中的应用，并给出了对太阳闭环跟踪的实验结果，与开环跟踪相比，光电导行效果明显，但还达不到NVST所期望的闭环精度0.3〞，文章分析了问题所在，并给出改进思路和下一步工作的研究重点。论文最后讨论了NVST控制系统的实现问题，包括系统结构的设计思想、拓扑结构和软硬件平台的选择与实现。论文以理论研究和实验相结合，各种测试数据表明，基本达到NVST控制系统的目标。
其他摘要
One Meter Solar Telescope (or named New Vacuum Solar Telescope, NVST for short) is a very important instrument for solar observation at present in China, and its main scientific target is the study of solar flow and magnetic fields through obtaining High-Resolution images and spectra at the wavelengths in the range 0.2 um to 2.5 um. The open loop tracking RMS of 0.5 arcseconds is required over a period of 30 seconds, and 5 arcseconds over a period of 10 minutes, and the RMS for autoguider is 0.3 arcseconds. The telescope can work normally under moderate breeze weather condition. An in-depth research on the NVST control system has been carried out to achieve the tracking precision and control system functions. In chapter 2, the azimuth and elevation servos of the NVST are studied in detail, the feedback control structure and mathematical models are built up, and special rate controller and positioning controller are designed to minimize wind disturbances. The results of numerical simulation and experiment on servo control systems have shown that the NVST can operate normally in moderate breeze condition with servo RMS error less than 0.5 arcseconds. In chapter 3, many factors about the NVST open loop tracking error are analyzed; the error model about axis angle encoder systems and pointing error model are established, respectively. From tracking a star, and positioning and analyzing tracking errors, the coefficients of the error model for the encoder systems are obtained. By pointing to many stars in different sky regions and analyzing pointing errors, coefficients of the pointing error model are determined. Experimental results show that the NVST open loop tracking precision is greatly increased with the two models. In chapter 4, the auto guide unit (AGU) is studied in depth, and how to measure the solar image movement on CCD precisely and quickly is the key for the NVST autoguider system. From the experimental results of several different measuring methods on solar image movement, a two-dimensional modified moment method is applied to calculate the centroid of solar image and obtain the image movement. The results by tracking the sun with or without the autoguider have illustrated that the AGU has a better tracking performance than the open loop control, but the AGU RMS is larger than 0.3 arcseconds as expected. The paper gives an analysis and explanation about the results, and presents some new ideas to improve the AGU performance. In the last chapter, the realization of the NVST control system is discussed, including the structural design of the control system network, topological structure, selection and realization for software and hardware platforms. In summary, the paper have carried out a thorough research on the NVST control system in theory and experiments, and a series of tests indicated that the NVST control system have achieved many intended demands. However, more in-depth research on focus image jetting caused by wind disturbance and more accurate measurement of solar image movement in AGU should be carried out.
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