自由返回轨道的P平面参数快速设计方法

针对自由返回轨道求解过程中地心轨道类型变化造成的B平面参数方法计算失败问题，提出一种基于P平面参数的自由返回轨道快速设计方法。首先，基于轨道半通径参数的普适性，给出了不同轨道类型的P平面参数定义，建立了以P平面参数为求解目标量的自由返回轨道求解模型。其次，给出了基于P平面参数的自由返回轨道快速设计方法，在构建的瞬时地月惯性系下，以平面双二体自由返回轨道作为初值，实现了高精度力模型下的自由返回轨道快速求解。对8种构型自由返回轨道的设计结果表明，P平面参数具有类似于B平面参数的大收敛域，且有效解决了轨道类型变化对计算的影响，可直接应用于中国后续月球探测任务轨道设计。

A Rapid Design Method of P plane Parameters for Free return Orbit

Aiming at the failure of the B plane parameter method due to the change of geocentric orbit type in the process of solving the free return trajectories, a rapid design method of the free return trajectories based on the P plane parameter is proposed. Firstly, based on the universality of orbital semi diameter parameters, the definitions of P plane parameters for different orbit types are given, and a free return trajectory solution model with P plane parameters as the solution target is established. Secondly, a rapid design method of free return orbit based on P plane parameters is given. Under the constructed instantaneous Earth Moon inertial system, the in plane dual two body free return orbit is taken as the initial value, and the rapid solution of free return orbit under the high precision force model is realized. The design results of eight free return orbits with different configurations show that the P plane parameters have a large convergence region similar to the B plane parameters, and the influence of the change of orbit types on the calculation is effectively solved, which can be directly applied to the orbit design of China’s subsequent lunar exploration missions.