登月火箭剩余运载能力估计与停泊轨道重规划

Residual Carrying Capacity Evaluation and Parking Orbit Re-planning for Lunar Exploration Launch Vehicle

针对载人登月火箭飞行过程中可能发生的推力下降故障,提出了基于剩余运载能力估计的停泊轨道重规划方法。通过系统分析全飞行剖面约束条件和地月转移轨道特点,提高了全程轨迹离线规划方法的收敛性,可用于分析推力下降故障后的剩余运载能力。对于无法进入地月转移轨道的故障,以航天员安全为目标设计了停泊轨道与飞行轨迹序贯重规划方法,在能够满足停泊轨道高度的前提下,进一步优化轨道面参数,为飞船实施二次救援创造良好初始状态;同时,通过入轨点预估降低入轨终端约束的非线性,并利用收敛性好的凸优化方法生成初始猜想,以提升序贯求解效率。仿真结果表明,本方法能够在火箭推力下降故障后,重新规划将飞船送入最优停泊轨道的飞行轨迹。

To cope with the potential thrust-drop malfunction of the manned lunar exploration launch vehicle,a parking orbit re-planning method is proposed based on the evaluation of the residual carrying capacity of the launcher.By analyzing the constraints of the whole flight profile and the characteristics of the Earth-Moon transfer trajectory systematically,the off-line trajectory planning algorithm improves convergence performance,and thus can be used to evaluate the residual carrying capacity as thrust-drop happens.For the situations that the launcher is not capable for injecting the transfer orbit,a sequential orbit/trajectory re-planning method is designed to guarantee the safety of the astronauts.On the premise of ensuring the altitude of the parking orbit,the elements about the orbital plane are further optimized to provide a favorable initial state for the subsequent rescue actions.Meanwhile,the nonlinearity of the terminal constraints is alleviated by the injection point forecast,and the initial reference is generated by convex optimization method with well convergence,thus,the solving efficiency of the sequential re-planning algorithm can be improved.Simulation results show the proposed method can generate the trajectory that transporting the spacecraft to the optimal parking orbit under the thrust-drop malfunction situation.