针对深空探测跳跃式再入返回飞行任务,提出了一种快速的再入制导算法,该算法基于模型预测控制(model predictive control,MPC)理论和近似动态规划(approximate dynamic programming,ADP)技术,将再入制导问题转化为两点边值问题,然后采用高斯伪谱法(Gauss pseudospectral method,GPM)求解该问题,实现快速制导计算。同时为了达到制导精度和制导效率的综合最优,提出了一种数值预报校正(numerical predictor-corrector,NPC)制导算法和快速再入制导算法融合的分段混合制导策略,该策略能对快速制导算法带来的制导偏差进行及时的修正,从而保证制导精度。蒙特卡罗仿真实验表明,与传统的数值预报校正制导算法相比,快速混合制导算法不仅能保证较高的制导精度,而且大幅减少了平均制导计算耗时,具有极大的在线应用潜力。
A fast entry guidance algorithm is raised for skip reentry mission of deep space exploration.The proposed algorithm converts the entry guidance problem to a two-point boundary value problem based on model predictive control (MPC ) theory and approximate dynamic programming (ADP ), and then the Gauss pseudospectral method (GPM)is employed to solve this problem efficiently.Meanwhile,in order to achieve balance on calculation efficiency and guidance accuracy,a piece-wise hybrid guidance strategy combining the nu-merical predictor-corrector (NPC)guidance algorithm and fast entry guidance is presented,which corrects the guidance error caused by the fast entry guidance algorithm in time so that the guiding precision can be guaranteed. Monte-Carlo numerical experiments demonstrate the hybrid fast guidance algorithm has good performance on guiding precision and decreases the computation time significantly,so it is quite suitable for on-line application.