大口径光电高分辨成像远镜主镜电液型高精度位姿控制系统  

Electrohydraulic highaccuracy position and orientation control system of the primary mirror for a large-aperture high resolution telescope

作　　者：李玉霞[1] 王建立[1] 郭鹏飞 张斌[1] 邓永停[1] LI Yuxia;WANG Jianli;GUO Pengfei;ZHANG Bin;YANG Xiaoxia(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033

出　　处：《光学精密工程》2023年第10期1487-1500,共14页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.11973041,No.12122304);中科院青促会会员项目资助(No.2019218)。

摘　　要：受自身重力、温度、不同工况下的外部干扰等影响,大望远镜主镜自由状态下位姿会产生巨大变化,导致后端光路不能对准,高分辨率成像质量下降,甚至图像飞出靶面。为消除主镜位姿变化对成像质量带来的影响,本文采用新型高精度电液控制系统对大望远镜主镜位姿进行控制。首先建立望远镜主镜位姿解算模型,分析主镜姿态变化原理;其次采用五个分区的多电机电液控制系统实现主镜姿态主动控制,建立各分区的液压控制系统模型,利用基于望远镜俯仰轴运动时位置误差的多元线性拟合前馈控制(EEFC)及线性自抗扰控制方法(LADRC)进行主镜位姿控制;最后进行测试,结果表明:4 m望远镜俯仰轴匀速运动时,可将主镜Z向平移精度从91.5μm提升到0.5μm,偏转角度精度从3 arcsec提升到0.05 arcsec。在1.2 m望远镜俯仰轴变速运动时,可将主镜Z向平移精度从5.04μm提升至0.2μm,角度偏移精度从0.65 arcsec提升到0.05 arcsec。在主镜上施加多点力促动器驱力时,主镜Z向位移精度从12.2μm提升到2μm内,角度偏移精度从1 arcsec提升到0.03 arcsec。通过测试验证,该控制系统可有效实现主镜光轴稳定,有效保证后端光路的对准与高分辨率自适应成像。Generally,owing to variations in gravity,temperature,and external disturbances under differing conditions,the positions and orientations of primary mirrors of high-resolution large-aperture telescopes often change significantly in the free state;in this scenario,subsequent optical axes cannot be aligned with the primary mirrors,causing optical misalignment errors and degraded adaptive high-resolution imaging qualities,sometimes even leading to image fly off from the field of view.To eliminate these imaging errors resulting from variations in the positions and orientations of primary mirrors(POPMs),this paper proposes a novel high-accuracy electrohydraulic control system for the POPM of a large telescope.For this,a mathematical model of the POPM is established for design and analysis for active control.First,a POPM resolving control model of an entire telescope is constructed,and the variation principle of the POPM is analyzed.Second,a five part muti-motor electrohydraulic control system is adopted to realize active control of the POPM.To guarantee control accuracy,we construct the electrohydraulic control system model of each part and use a multivariate linear fitting feed forward controller based on the position error resulting from a change in the telescope elevation;meanwhile,a linear active disturbance rejection controller is adopted for POPM control.Finally,experiments on large telescopes are performed.When the elevation of a 4 m telescope moves at a constant speed,the Z shift can be reduced from 91.5μm to 0.5μm,and the deflection shift can be controlled under 0.05 arcsec from 3 arcsec.Next,when the elevation of a 1.2 m telescope moves at a variable speed,the Z shift can be reduced from 5.04μm to 0.2μm,and the deflection shift can be controlled under 0.65 arcsec from 0.05 arcsec.Further,when multipoint force actuators are added to the primary mirror,the Z shift can be reduced from 12.2μm to 2μm,and the deflection shift can be controlled under 0.03 arcsec from 1 arcsec.This can effectively realize the o

关 键 词：大口径望远镜 主镜位姿控制 多电机 电液系统 

分 类 号：TP394.1[自动化与计算机技术—计算机应用技术] TH691.9[自动化与计算机技术—计算机科学与技术]