轨道转移航天器紫外自主导航的应用

Application of Ultraviolet Autonomous Navigation for Orbit Transfer Spacecraft

应用紫外敏感器可较高精度地实现航天器全程自主导航。为解决其应用于中高轨不全程可见以及地心距测量误差大的问题,将紫外敏感器采用中心视场和环形视场同轴的结构,用中心视场观测地球,仅以地心方向矢量作为观测量降维输出,采用扩展卡尔曼滤波算法估计出航天器的位置和速度。对该方案建立算法模型,以轨道高度1 000~36 000 km的转移轨道为例仿真验证,研究测量精度、采样周期对导航精度的影响,分析系统可观性。仿真结果表明,系统可观,紫外敏感器测量精度越高导航精度越高,地心方向测量误差不大于0.05°时导航精度位置误差不超过4km、速度误差不超过0.5 m/s,方案有效可行。

To improve the performance of ultraviolet sensor applied to middle and high orbit transfer spacecraft,an autonomous navigation scheme based on ultraviolet sensor is proposed. By observing the ultraviolet image of earth with sensors,geocentric vector information is provided and then the orbit of the spacecraft can be determined. The scheme is designed without range measurements,since range error to earth is too huge to use during orbit transfer from height 1 000 km to 36 000 km. The algorithmic model is established,and simulation is taken using extended Kalman filter with orbit data and measurement data. Apart from the influence of sensor measurement precision,sampling period on the navigation accuracy is studied,and observability properties are investigated. The simulation results show that the scheme is effective and the navigation filter can also converge to acceptable accuracy.