一种四通式星敏感器支架结构设计与分析

Design and Analysis of a Four-way Star Sensor Assembly

为了提高在轨几何定标精度,遥感卫星高精度姿态测量和控制是关键环节之一;星敏感器是最精密的姿态测量部件,提高星敏感器的在轨指向精度意义重大。星敏感器的指向误差主要是由星敏感器支架(以下简称星敏支架)受空间环境影响产生的变形所导致。文章针对某遥感卫星星敏感器指向小于2″精度需求,设计了一种四通式星敏支架,可提供3台星敏感器的安装接口,实现星敏感器一体化安装,并对星敏支架的热稳定性进行了研究。采用有限元法对星敏支架进行了刚度分析,并结合最小二乘法分析了在轨极端工况下温度变化引起星敏感器光轴的变形量。结果表明:星敏支架的带载基频为119Hz,整机振动工况下,星敏感器安装面最大响应不超过8gn,可为星敏感器提供良好的力学环境安装界面;在轨期间星敏支架最大温度波动小于0.5℃,星敏感器指向精度为1.2″,能够实现星敏感器指向精度要求,可为后续星敏支架设计提供参考。

In order to improve the accuracy of on-orbit geometric calibration,high precision attitude measurement and control of remote sensing satellites is one of the key steps.The star sensor is the most precise attitude measurement component,and it is of great significance to improve the on-orbit pointing accuracy of star sensor.The pointing error of the star sensor is mainly caused by the deformation of the star sensor frame under the space environment.Aiming at the pointing accuracy less than 2 for a remote sensing satellite s star sensor,a four-way star sensor bracket is designed in this paper.The installation interface of three star sensors can realize the integrated installation.The structure and thermal stability of the bracket are studied.The stiffness is analyzed by the finite element method,and the deformation of the optical axis is analyzed by the least square method.The results show that:the base frequency of the star sensor bracket is 119 Hz;the maximum response of the installation interface of star sensor under the vibration condition of the whole camera is below 8 gn,showing that the bracket can provide a good mechanical environment for the star sensor;the maximum temperature fluctuation of the star sensor bracket is less than 0.5℃,and the pointing accuracy of the star sensor is 1.2″.The four-way star sensor assembly can meet the requirements of high precision positioning of remote sensing satellites,giving a good reference for future designs.