1米太阳望远镜光谱仪像旋转及消旋控制

光谱仪是1 m太阳望远镜的主要终端设备之一,该望远镜采用地平式的机架结构和修正的格里高利光学系统。在望远镜跟踪太阳时,由于地平式望远镜的自身运动特点和光学系统中平面反射镜的存在,其光谱仪狭缝所在平面上的太阳像随时间绕主光轴旋转,因此光谱仪必须进行消旋才能正常工作。首先深入研究了光谱仪狭缝平面上像的旋转变化,分析其旋转范围、速度和加速度随时角变化的特性,然后根据光谱仪消旋精度并结合像的旋转特性提出伺服系统位置检测和驱动电机的主要性能指标,最后给出光谱仪消旋伺服控制方案。

Image-Field Rotation and Control of Counter Rotation for the Spectrograph of the 1m Solar Telescope of the Yunnan Observatory

The 1m solar telescope of the Yunan Observatory has a spectrograph as one of its main terminal instruments.The telescope has an altazimuth mounting structure and a Gregorian optical system.In the process of tracking the sun,the solar image on the slit plane of the spectrograph rotates around the main optical axis because of the kinetics of the mounting structure and mirrors.Such image-field rotation should be compensated for the spectrograph to work properly.We first give an in-depth study of the image-field rotation on the slit plane,and analyze the variations of rotation angle and acceleration of image-field rotation with the solar hour angle.We subsequently provide key parameters about position detection and driving motors of the counter-rotation system based on the specifications of image-field rotation and requirement on precision of counter rotation.We finally give a design of the servo control of counter rotation for the spectrograph.