大型高精度消像旋机构的设计与验证  

Design and verification of large high precision derotator

作　　者：芮道满 张程 李文茹[1,2] 李程 文丰艾[1,2] 鲜浩 RUI Daoman;ZHANG Cheng;LI Wenru;LI Cheng;WEN Fengai;XIAN Hao(National Laboratory on Adaptive Optics,Chengdu 610209,China;Institute of Optics and Electronics,Chinese Academy of Sciences,Chengdu 610209,China)

机构地区：[1]自适应光学全国重点实验室,四川成都610209 [2]中国科学院光电技术研究所,四川成都610209

出　　处：《光学精密工程》2024年第12期1849-1856,共8页Optics and Precision Engineering

基　　金：国家自然科学基金(No.61901449)。

摘　　要：在大口径望远镜巡天观测中,需要成像相机对指定天区长时间曝光,受地球自转的影响,长曝光图像会产生旋转现象。消像旋机构是为了抵消地球自转对成像质量的影响,使成像光斑在相机上位置稳定、能量集中。墨子巡天望远镜采用相机旋转的方式实现消像旋功能,消像旋机构要求具备承载能力≥250 kg、转速>20′/s和角定位精度≤2″。本文通过对影响消像旋机构承载能力、转动速度和定位精度的因素分析,采用高精度转台轴承结合轻量化转轴实现了高精度和高刚度轴系设计,轴系晃动为1.9″。传动系统采用谐波减速器结合圆柱直齿轮副两级传动,实现了低转速和高角分辨率。利用双读数头绝对式圆光栅测量转角误差并进行位置控制补偿,实现了角定位精度优于1.1″。墨子巡天望远镜成像图像在经过消像旋机构补偿后,光斑能量集中、无画圆,实现了高质量成像的目标。In the observation of large survey telescopes,the camera is required to expose designated sky area for a long time.The long exposure image is rotated due to the Earth’s rotation.The derotator is used to counteract the impact of the Earth′s rotation on the imaging quality,ensuring stable position and energy concentration of the imaging spot on the camera.Camera rotation method is used as the derotator of Mozi sky survey telescope.The derotator requires a bearing capacity of≥250 kg,a speed of>20′/s,and an angular positioning accuracy of≤2″.This article analyzed the factors that affect the load-bearing capacity,rotational speed,and positioning accuracy of the derotator.High-precision turntable bearing combined with lightweight rotating shaft were adopted to achieve high-precision and high stiffness shaft in this paper.The shaking of the shaft system was 1.9″.The transmission system adopted a harmonic reducer combined with a cylindrical spur gear pair for two-stage transmission,achieving low speed and high angular resolution.The absolute circular grating with dual reading head was used to measure the angle error.The compensated angle positioning accuracy was better than 1.1″.The survey image with concentrated energy spot and no image rotation after the compensation of the derotator.The Mozi sky survey telescope achieves the goal of high-quality imaging.

关 键 词：巡天望远镜 消像旋机构 角定位精度 高质量成像 

分 类 号：TH751[机械工程—仪器科学与技术]