基于显式制导的月地返回轨道中途修正研究

On Midcourse Correction of Moon-Earth Return Trajectory Based on Explicit Guidance

月地返回轨道存在各种摄动误差,终端约束复杂,有必要对其进行中途修正研究。显式制导法通过二体轨道与精确轨道之间的差别进行多次迭代求解给定时刻所需的修正速度。文章利用显式制导法,采用月球段及地球段分段进行中途修正的策略,给出了基于分段落点预报显式制导的月地返回轨道中途修正方案。该方案无需计算雅克比矩阵,算法简单、计算快速、实用性强,能满足再入点参数要求。算例仿真与蒙特卡洛仿真验证了该方案的适用性。

The research on the midcourse correction necessary, as nominal orbit is perturbed by several of Moon-Earth return trajectory is disturbance sources and boundary constraints is complicated. The solution of characteristic velocity was got through the explicit guidance method by using the iterations algorithm based on the difference between the two-body orbit and precise trajectory. As the midcourse correction strategy was divided into moon-section and earth-section, the explicit guidance correction schemes of Moon-Earth return trajectory based on subsection location points prediction was presented. The scheme can satisfy the reentry point parameters constraints and can he used widely in practice, as the algorithm is simplified to overcome disadvantages of the differential correction algorithm which requires a numerical Jacobian matrix. Finally, the adaptability of the scheme was validated by numerical simulation and Monte-Carlo simulation.