基于UKF参数估计的地月自由返回轨道设计

为快速简便地设计地月自由返回轨道,提出了一种基于UKF参数估计算法的地月自由返回轨道设计方法。该算法不仅避免了传统数值方法推导相关梯度矩阵的复杂性,而且只需基于地月系统二体模型给出猜测初值,从而显著降低了自由返回轨道设计的难度,将地月自由返回轨道对应的两点边值问题的求解转化为参数估计问题,该算法可以得到高精度模型下收敛的精确解。数值仿真结果表明:该算法结构简洁,求解效率较高,所得结果精确且具有良好的鲁棒性,可以作为地月自由返回轨道设计的一个有力工具。

Design of Lunar Free-Return Trajectories Based on UKF Parameter Estimation

A fast and convenient design-method based on UKF parameter estimation is proposed for lunar free-return trajectories. The method proposed avoids calculating the Jacobian matrix and obtains large convergence ability compared with the common differential-correction method. Given that the initial estimate of the free-return trajectory is generated under the two-body Earth-spacecraft model, the difficulty of guessing a good initial estimate is greatly reduced. Through solving the converted parameter estimation problem using the method proposed, the converged final solution can be found under a high-fidelity gravitational model by a few iterations. Despite its simplicity, the method is proves to be quite effective in finding the solution of lunar free-return trajectories with great numerical accuracy.