高超声速飞行器动力学规划的落点区域计算

The Calculation for Landing Footprint of Hypersonic Vehicle Based on Dynamics Programming

高超声速飞行器的再入过程十分复杂,已知初始状态推断落点区域对飞行器再入航迹规划具有重要意义。本文提出一种基于动力学规划求解高超声速飞行器落点区域的方法。该方法在满足再入轨迹的各种约束条件前提下,在能量-阻力空间里描绘出标称阻力边界曲线,通过反馈线性法对其进行跟踪得到实际可用的上下边界,再经插值计算得到符合约束条件的阻力方案。纵向轨迹采用反馈线性法跟踪得到,而横向控制则通过不同时刻的侧向机动实现。选取阻力最大和最小点作为再入落点区域的最上和最下端,将倾侧角恒为正的点和恒为负的点作为最左和最右端点,由此组成了再入落点区域的边界。该方法通过了计算机仿真可行性验证,得到了精确的落点区域。

Computing the landing footprint based on current state is of great significance for the reentry trajectory planning due to the complexity of hypersonic vehicle＇s reentry.A method based on dynamics programming to obtain the landing footprint of the hypersonic vehicle is presented in this paper.Firstly,it creates the nominal drag boundary curve in the energy-drag space to meet the path constraints,and then the nominal drag boundary curve is tracked by the feedback linearization method to acquire the feasible boundary.Then an interpolation method is utilized to create the feasible drag family.While the vertical profile is acquired by tracking feasible drag profile,the bank reversal is added to control the lateral profile.Finally,the far boundary and the near boundary of landing footprint are acquired by choosing the biggest and the smallest feasible drag profiles and then the left and the right boundaries are achieved by making the bank angle be constant positive and constant negative,which form the landing site zone.This method is proven to be feasible by the simulations and the accurate results are acquired.