TSTO运载器一级返场轨迹优化设计与在线生成

对水平起降两级入轨（TSTO）运载器一子级返场轨迹优化和轨迹在线生成问题进行了研究。首先，给出了较独特的一子级再入轨迹设计策略：先给定侧向剖面，再分段优化求解三维轨迹。针对返场过程的大幅转向需求，设计了形式简单的倾侧角-航向角偏差剖面，并定义了具有不同任务的航向转弯段和航向微调段；针对一子级宽速域气动变化显著特点，为避免轨迹跳跃，定义了增高减速段和下降滑翔段，并采用分段优化策略求解三维轨迹。其次，针对分离扰动造成的一子级初始状态偏差，扩展了自适应高维伪谱插值（AMPI）算法的参数空间，并将其应用于返场轨迹在线生成问题。仿真结果表明，设计的倾侧角剖面能够在倾侧角不翻转的前提下调整飞行航向对准着陆场，设计的分段优化策略能够保证高度曲线平稳无跳跃，采用的自适应高维伪谱插值算法能够在分离扰动影响下快速准确地实现在线轨迹生成。

TSTO vehicle first-stage return trajectory:Optimization and onboard generation

First-stage return trajectory optimization and onboard generation of the horizontal launch Two-Stage To Orbit (TSTO) reusable vehicles are studied. The optimization strategy of the first stage return trajectory is firstly proposed: the lateral profile is given prior to solution of the three-dimensional trajectory by piecewise optimization. A lateral bank angle profile is designed to meet the large steering requirements during the first stage reentry process. In view of the remarkable characteristics of aerodynamic variations in the wide velocity domain of the first stage, the multi-segment optimization strategy is designed to avoid repeated trajectory jumps, and Gauss Pseudospectral Method (GPM) is used to design the three-dimensional trajectory. To solve the initial state deviation caused by separation disturbance of the TSTO vehicle, the parameter space of the Adaptive Multivariate Pseudospectral Interpolation (AMPI) method is extended to generate the onboard trajectory for the first stage. The simulation results show that the proposed lateral bank angle profile can ensure the alignment of the flight course with the landing field without the need for repeated reversals of the bank angle, and the multi-segment optimal strategy can ensure a stable trajectory, and the AMPI method can generate onboard trajectory quickly and accurately under the condition of large initial deviations.