考虑禁飞区规避的空天飞行器分段预测校正再入制导方法

针对空天飞行器再入制导问题，提出一种考虑禁飞区规避的分段预测校正制导方法。在再入段前期采用剩余航程作为目标函数，后期引入预测落点偏差作为目标函数进行制导指令求解，同时确定倾侧角幅值和符号，兼顾了计算效率与终端制导精度。在此基础上，对于再入过程中的禁飞区规避问题，把禁飞区分为两类，增加了通过倾侧角幅值修正策略实现侧向规避制导的逻辑，可适用于无法单独通过倾侧角反转规避禁飞区的情况。最后，通过开展考虑再入初始状态和气动品质不确定性的蒙特卡罗仿真，验证了提出的分段预测校正制导方法可以有效引导空天飞行器规避禁飞区，与单段目标函数预测校正方法相比，具有更高的制导精度。

A Piecewise Predictor corrector Re entry Guidance Algorithm with No fly Zone Avoidance

To enhance the accuracy of reentry guidance, an improved predictor corrector guidance algorithm is presented by introducing a piecewise objective function. In the early stage the function is defined as range to go while in the terminal stage as drop point error.The modified objective function can generate not only the amplitude but also the symbol of the bank angle without the cross range corridor so as to guarantee the computational efficiency as well as the guidance accuracy. Furthermore, the no fly zone avoidance is taken into consideration. In addition to classifying the no fly zone into two types, an amplitude correction mechanism is employed to cope with the situation where the no fly zone cannot be avoided only by the bank angle reverse strategy. The Monte Carlo simulation with random initial dispersions and model uncertainties demonstrates that the proposed algorithm is effective on no fly zone avoidance and has higher guidance accuracy than single objective function method.