Gauss伪谱法的再入可达域计算方法

为了加快优化速度和提高优化质量,提出一种基于Gauss伪谱法的再入可达域计算方法。鉴于再入时一般采用固定的攻角剖面,将攻角作为状态变量,仅对倾侧角进行单变量寻优。优化过程中,再入纵程被视为终端约束,以获取不同纵程下的最大横程,将速度倾角视为过程约束,以消除弹道的跳跃现象。通过仿真,求解出了通用航空飞行器的再入可达域,结果与间接法的理论证明一致。

Landing Footprint Generation of Entry Vehicle Based on Gauss Pseudospectral Method

Entry Landing footprint is a significant index to flight capability of entry vehicle. The research on footprint generation is useful in trajectory planning and in the case of failed vehicle landing. The paper takes advantage of Gauss pseudospectral method to generate footprint. To reduce calculation time and improve optimization result, attack angle is regarded as a state variable and only bank angle is optimized, which is reasonable since attack angle profile is often predesigned in engineering. Down-range of vehicle is regarded as event constraint, based on which maximum cross-range is calculated. Flight path angle is regarded as path constraint to eliminate skips on the trajectory. Through simulation, the footprint of CAV-H is generated, which is in accordance with the theoretical analysis of indirect optimization method.