基于双模型直接配置法的航天器轨迹优化

Spacecraft Trajectory Optimization Using Dual-Model Direct Collocation Method

针对有限推力航天器轨迹优化问题,提出一种HLDL双模型直接配置法将航天器的飞行轨迹划分为最大推力弧段和零推力弧段。在两种弧段上分别采用了两种不同的建模方法并利用埃尔米特插值法将最优化问题转化为非线性规划问题(NLP)。给出了节点和配置点数目的选取与所在弧段的平均曲率大小成正比的法则,解决用于有限推力航天器轨迹优化所涉及的关键问题。仿真结果表明提出的方法能有效的解决飞行器轨迹优化问题并具备很强的鲁棒性。

This paper deals with spacecraft trajectory optimization and presents a direct collocation method to di- vide the entire trajectory into the maximum thrust arcs and the zero thrust arcs. Different mathematical models are a- dopted to enhance the performance of the direct collocation method. The optimal control problem is transformed into a nonlinear programming problem （NLP） based on Hermite interplation. Finally, nodes and collocation points are allocated according to the law that the number of points varies inversely with the size of approximate mean curvature. Simulation results show that the method proves its effectiveness and robustness in solving spacecraft trajectory optimi- zation problem.