绕月卫星软着陆最优轨道控制策略分析

STRATEGY ANALYSIS OF THE OPTIMAL TRAJECTORY CONTROL IN LUNAR SOFT LANDING

对于绕月卫星的软着陆轨道问题,运用天体运动规律构建了物理模型,并利用最优化原理,把软着陆轨道控制问题转化为非线性规划问题,通过正确控制状态改变点来拟定最优控制策略.文章以嫦娥三号卫星为例,参考相关实际数据,给定相应初始条件,结合Matlab的计算结果,给出了多个相关参数随时间的变化曲线,在此基础上详细分析了卫星软着陆过程中的6个分阶段,定性讨论了在此过程中可能影响着陆精度的多种误差因素,并且通过敏感性分析给出了提升安全着落概率的方法.

To deal with the soft landing orbit of sircumlunar satelite,the model is built under the motion of celestial bodies.Under the principle of optimality,the problem of soft landing trajectory control is changed into the problem of nonlinear programming.The best control strategy is made through the correct control of state variations.Taking Chang＇e-3 for example,reading related real datas for reference,giving initial conditions,the changing curves of the relevent parameters as the time goes by are given out,and the 6phases of soft landing are detailedly analysed,the errrors that may affect the landing accuracy are qualitatively discussed.After the sensitivity analysis,the method has been demonstrated to increase the probability of safety landing.