星敏感器支架的指向性标定及校正

Directivity calibration and correction of bracket for star sensor

为保证星敏感器支架安装后具有高精度的指向性,提出了一种星敏感器支架定量修研的技术方法,首先通过构造虚拟水平轴建立星敏感器支架坐标系,然后利用经纬仪交互测量和逐级求解方法获得星敏感器支架和相机任意两坐标轴的夹角关系。根据该结果进行了星敏感器支架实际坐标系与相机坐标系姿态变换矩阵的求解,利用星敏感器支架与相机坐标系的技术指标要求,进行了星敏感器支架理论坐标系与航天相机坐标系的姿态变换矩阵求解。然后以相机坐标系进行中间传递,获得了星敏感器支架实际坐标系到理论坐标系的姿态变换矩阵。根据该结果精确求解了星敏感器支架的修调量。通过试验研究表明利用该方法装调完成的星敏感器支架,经过两次修研迭代,其指向精度由最初的760″提升至10″以内。证明了该方法的有效性,同时星敏感器支架的指向性标定及校正也可指导其他有空间自由角度关系的两部件的精密装调。

In order to ensure the high-precision pointing of bracket for star sensor after installation, a technical method for quantitative grind of bracket for star sensor was proposed. Firstly, we established the star sensor bracket ’s coordinate system by constructing the virtual horizontal axis, then obtained the angle relationship between any two coordinate axes by the theodolite interactive measurement and sequential solving strategy.According to the results, we got the posture transformation matrix between star sensor bracket’s actual coordinate system and the space camera ’s coordinate system. By the technical requirements of the star sensor bracket ’s installing, we acquired the posture transformation matrix between the ideal star sensor bracket ’s coordinate system and the space camera’s coordinate system. Then, we obtained the posture transformation matrix from the actual coordinate system to the ideal coordinate system by bridge of the camera coordinate system. According to this result, the corrective value of bracket for star sensor was accurately solved. The experimental research shows that this method can improve the star sensor bracket’s pointing accuracy from the initial 760″ to less than 10″ after two rounds of iteration, which proves effectiveness of the method. At the same time, directivity calibration and correction of bracket for star sensor can also guide the precise assembly and adjustment of other two components with spatial free angle relationship.