基于Riccati方程解的再入飞行器制导律设计

提出一种再入飞行器纵向制导律设计方法。首先对纵向运动方程沿着实际轨道线性化,然后利用线性最优调节器原理设计制导律。在每个制导周期内求解代数R iccati方程,利用其正定解构造反馈控制律,与标准轨道的控制量叠加后形成全量控制,用于实际再入轨道的制导。仿真结果表明,所设计的制导律对再入初始偏差具有较强的鲁棒性,同时它也能较好地补偿由于气动参数和大气密度摄动造成的航程误差,从而保证落点精度。

Design of Guidance Law for Reentry Vehicles Based on the Solution of Riccati Equation

A designing method for the longitudinal guidance law of reentry vehicles is presented in this paper.First,the longitudinal dynamic equations are linearized about the actual trajectory.Then the guidance law is designed by using the linear optimal regulator theory.In each guidance period,the algebraic Riccati equation is solved and its solution is used to construct the feedback control law.The feedback control plus the nominal one is used to guide the actual reentry trajectory.Simulation results show the proposed guidance law is robust to deviations from reentry initial states and it can compensate the range error resulting from the perturbations of aerodynamic parameters and atmospheric density.So the landing point precision is guaranteed.