月球软着陆多项式制导控制方法

Polynomial Guidance Law for Lunar Soft Landing

以燃耗最优性为出发点,假设垂直方向上的最优着陆轨迹可以由一关于时间的三次多项式来完全表示,根据开环最优制导设计了月球软着陆的多项式制导控制律。通过对加速度矢量之间的几何关系进行分析可以得到制导控制量-推力方向角的显示表达式。该制导律表达式是剩余时间的函数,而给出的剩余时间表达式只与着陆器的状态变量和终端约束有关,无须进行迭代计算,是一种易于实现的次优闭环实时制导控制方法。

With the assumption that vertical optimal landing trajectory can be represented as three-order polynomial,explicit guidance law is designed for lunar soft landing according to open-loop optimization criterion.The explicit expression of thruster directional angle,that is control variable,is obtained by analyzing the geometrical relation of acceleration vectors.The guidance law proposed in this paper is function of local time that is relative to lander's state variable and landing final constraint only.The gu...