基于高斯问题的近最优再入预测制导方法研究

The Sub-optimal Prediction Guidance Algorithm for the Reentry Vehicle Based on the Gauss Equation

再入过程中利用解算高斯问题建立落在地面固定目标的开普勒轨道,由于干扰力的存在,再入飞行器将偏离这条轨道,为此需要对再入飞行器进行速度修正。速度的修正方案有两种:一种是使修正后的轨道返回到事先装订到计算机上的标准轨道上,即标准轨道法;另一种是根据落点重新建立一条可落在固定目标的轨道,即预测制导法。文中利用牛顿迭代法对高斯问题进行优化,得到了可重新落在地面目标的最小速度修正量,得到了一种快速的近最优预测制导算法。仿真结果表明:此算法简单,运算速度快,需用过载小,且得到了较小的脱靶量。

During the reentry of the spacecraft, Keplerian ellipse is established by resolving Gauss equation, which will guarantee the vehicle accurately reach the fixed target on the ground. Affected by the interference force, the reentry vehicle will deviate the theoretical track. It is necessary to correct the velocity qf vehicle, which can be realized by two means： one is named nominal orbit method, in which the vehicle is forced to the nominal orbit saved in the computer in advance, and the other is called predictive guidance method, which means that a new orbit is created according to the landing point to ensure that the vehicle reaches the target track. In this paper, Newton iteration method is introduced to optimize the Gauss equation. By this method, the minimum velocity correction to guarantee the vehicle reaching the right target is gotten and a fast sub-optimal prediction guidance algorithm is obtained. Simulation result shows that the algorithm has the merits of simple, fast computing, small overload, and satisfied miss distance.