基于滚动时域控制的再入轨迹跟踪制导律

为了提高再入制导的实时性和鲁棒性，设计一种标准轨迹跟踪制导方法。首先将参考轨迹的跟踪问题转化为轨迹状态调节问题，进一步转化为一个线性时变系统的最优控制问题；然后采用滚动时域控制结合基于间接Legendre伪谱法的最优反馈控制算法设计出一种易于在线实现的制导律。基于上述工作完成了亚轨道飞行器（suborbital reusable launch vehicle, SRLV）返回制导过程的3自由度数值仿真研究工作。数值算例说明，该制导方法在初始点状态存在较大范围偏差和气动参数存在较大误差的情况下具有良好的鲁棒性。

Trajectory tracking guidance law for reentry based on receding horizon control

To improve the instantaneity and robust ness, a reference trajectory guidance scheme for the reentry is introduced. The trajectory tracking problem based on the obtained reference-trajectory is converted into a trajectory state regulation problem which is actually an optimal control problem of a linear time varying system. And a robust guidance law combines the benefits of the indirect Legendre pseudo-spectral method and the receding horizon control method is applied to the problem. The three degree of freedom guidance for the reentry of suborbital reusable launch vehicle (SRLV) is implemented. Finally, numerical results indicate that the guidance scheme is robust to the presence of a wide range of initial uncertainties and aerodynamic parameters disturbance.