星敏感器热稳定性的试验分析方法

星敏感器作为高精度姿态测量仪器,在轨工作时易受热环境的影响。针对仿真分析难以精确建立星敏感器光-机-热模型的问题,提出了一种星敏感器热稳定性试验分析方法,通过加热真空罐中的安装面和遮光罩来模拟星敏感器的在轨热环境,利用静态光星模拟器模拟星空,通过观察星敏感器输出姿态的变化评价星敏感器的三轴热稳定性。试验过程中通过自准直仪对安装面棱镜的测量值剥离安装面热变形对姿态测量的影响,经过分析后可知误差在4.5%以内。对某型号高精度星敏感器进行试验,结果表明:当遮光罩温度由27.3℃升至110.6℃时,星敏感器光轴绕x轴的偏移量为2.9″,绕y轴的偏移量为1.2″,绕z轴的偏移量为2.6″;当星敏感器安装支架控温精度为(20±0.3)℃时,星敏感器光轴的偏移量为±0.18″,满足高精度星敏感器的热稳定性指标。

Method for Experimental Analysis of Thermostability of Star Sensors

A star sensor is a highly accurate attitude measurement device,but it is susceptible to the thermal environment.Moreover,it is difficult to establish an optical-machine-thermo model of a high-precision star sensor by simulation.Accordingly,an experimental analysis method is proposed to simulate on-orbit thermal environment of the star sensor by heating the mounting surface and baffle in a vacuum tank and simulate the star using static star simulator.The triaxial thermostability of the star sensor can be evaluated by observing its output.A prism mounted on a mounting surface was used to remove the thermal deformation of the mounting surface by auto-collimation with an error margin of 4.5%.Results show that when the baffle is heated from 27.3℃to 110.6℃,the drifts of the x,y,and z axis are 2.9″,1.2″,and 2.6″,respectively.When the temperature control accuracy of the mounting bracket is(20±0.3)℃,the optical axis drift is±0.18″,which meets the requirements of thermostability indicators of the high-precision star sensor.