一种星敏感器系统热设计方法及试验验证

Thermal Design Method and Experimental Verification of Star Sensor System

目前,国内机构针对星敏感器的温控研究与设计较少,多集中于星图的图像处理和图像算法的优化。着重以星图中目标能量变化、信噪比、质心定位误差等参数为指标,分析温度对该星敏感器的热影响,从而实现高精度星敏感器在空间复杂热环境下的可靠应用。进一步基于星敏感器的结构及热分布,对星敏感器进行热设计及散热路径优化,提出星敏感器热电制冷器(Thermo electric cooler,TEC)的热控措施。以典型在轨高温工况与低温工况为例,利用有限元仿真软件进行该热设计的有效性与合理性仿真分析。在以上的设计与分析基础上,完成一套温度控制系统,通过模拟星敏感器在高温工况下的环境条件,使用热电制冷方式对星敏感器采取制冷措施,使星敏感器探测器温度维持在20℃±3℃,达到温控指标,保证星敏感器能够在恶劣温度环境下持续提供高精度姿态信息。重点阐明热环境因素与成像质量之间的关系,完成温度与星点识别精度的关联性分析,为后续星敏感器热控设计及定姿精度提升提供参考。

At present,the research and design of temperature control for star sensor in domestic institutions are less,and they focus on the image processing and image algorithm optimization of star map.The thermal effect of temperature on the star sensor is analyzed in this manuscript by taking the target energy change,signal-to-noise ratio and centroid positioning error as indexes,so as to realize the reliable application of high-precision star sensor in complex space thermal environment.Furthermore,based on the structure and thermal distribution of star sensor,the thermal design and heat dissipation path optimization of star sensor are carried out,and the thermal control measures of TEC are proposed.The temperature distribution of star sensor is discussed in typical high temperature and low temperature conditions.The validity and rationality of the thermal design are simulated and analyzed by finite element simulation software.On the basis of the above analysis and design,a set of temperature control system is completed.By simulating the environmental conditions of the star sensor under high temperature conditions,the thermoelectric refrigeration method is used to cool the star sensor,so that the temperature of the star sensor detector maintains at 20℃±3℃.The relationship between thermal environment factors and image quality is clarified,and the correlation analysis between temperature and star recognition accuracy is completed,which provides a direction for future improvement of star sensor attitude determination accuracy.