基于夏氏最小二乘的轨道控制力系数辨识

在航天器轨道捕获、轨道维持和空间目标碰撞规避中都需要进行航天器轨道机动。针对航天器轨道机动过程中推力器的推力系数为装订常数，没有根据在轨工作实际进行优化而导致出现较大误差的情况，对控制力拟合系数进行辨识，作为修正控制参数以补偿轨道控制误差的依据，提高轨道控制精度。统计分析在轨管理的典型航天器平台及其发动机的轨道控制历史数据，分析轨道控制理论和在轨控制数据拟合建立轨道控制经验模型，用当前可测量的系统输入和输出预测系统输出的未来演变，得到不同工作情况下实际轨道控制误差与控制参数及其他主要影响因素之间关系的经验公式，为轨道控制策略决策提供参考。选取轨道半长轴控制量300m以上和300m以下的两类近地卫星，对其轨道控制历史数据进行分析，经实际数据测试，采用夏氏法进行推力系数拟合后预测的速度变化量精度较高。该种计算方法利用了轨道控制历史数据，计算方法简单，提高了轨道控制速度增量的预测精度，对轨道控制实施具有参考意义。

Orbit control force coefficient identification by Charp recursion method

Spacecraft orbit maneuvers are required in spacecraft orbit capture, orbit maintenance and obstacle avoidance. Considering the fact that during spacecraft orbital maneuver, the thrust coefficient is the binding constant, error can be great due to the unoptimized parameter. The fitting coefficient of the control force is identified as a correction control parameter to compensate for the orbital control error, so as to improve the accuracy of orbit control. The historical orbit control data of typical spacecraft platform and its engine were analyzed in a statistical way. By analyzing the previous orbit control theory and in orbit control data, the orbit control empirical model was established. With the input and output of the current measurable system, the future evolution of system output was predictable and the empirical formula of the relationship between the error of actual orbit control and the control parameters under different working conditions was concluded.Two types of Low Earth Orbit (LEO) satellites with semi major axis variation above and below 300 meters were selected to analyze historical data of orbital control. After the actual data test, the accuracy of the velocity variation forecast after the thrust coefficient fitting by the Charp recursion method is higher. This kind of calculation method makes use of historical data of orbit control, and the calculation method is simple, which improves the prediction precision of orbit control speed increment and has reference significance for the implementation of orbit control.