中国科学院云南天文台机构知识库

针对中国巨型太阳望远镜的8m环形拼接主镜设计方案,建立了其边缘传感器和光学传感器响应子镜面内位移量的模型,进而分析了子镜面内位移对环形拼接主镜面形保持的影响。考虑了望远镜桁架因望远镜指向和温度改变引起子镜面内位移量,并发现该位移量会破坏环形拼接主镜的面形保持效果。为解决面内位移对环形拼接主镜面形保持的不利影响,提出了相应的主镜控制模型改进方案。改进方案是:通过在子镜拼缝处加装两组间隙量传感器和一组剪切量传感器,利用增加的探测量估算子镜的面内位移量,进而修正边缘传感器与光学传感器的设定值。当间隙量和剪切量的探测精度好于23nm时,改进方案可以满足中国巨型太阳望远镜的8m环形拼接主镜方案的面形保持要求。 

Against 8m Ring Solar Telescope, major project of Chinese Giant Solar Telescope, firstly, this paper is establishing a model of the edge sensor and optical sensor response in segments displacement, analyzing the segments in-plane displacement impact on the original primary mirror control strategy. Considering steel truss of the telescope, the segments' displacement due to motion of zenith angle and undulating of temperature makes an abnormal primary mirror. Thus, improving the primary mirror control strategy is proposed. The advanced primery mirror control strategy of 8 meter Ring Interferometric Telescope includes edge sensor attached detectability of gap, adding shear sensor among the edge of neighbor segments, estimating height discontinuities and tip－tilt reading of optical sensor by using sensitivity of gap and shear, and keeping the edge sensor reading and optical sensor reading in estimated reading. Finally, it figures out that the detection accuracy of the gap and shear less than 23nm makes advanced control strategy meeting design specification of Chinese Giant Solar Telescope.