基于遗传算法的小推力星际转移轨道设计与控制优化方法

Low Thrust Interplanetary Transfer Trajectory Design and Control Optimization Based on Genetic Algorithm

对用遗传算法搜索小行星探测任务的低能量星际转移窗口并进行小推力转移轨道控制优化的方法进行了研究。通过对星历的计算和对兰伯特问题的求解,将低能量星际转移窗口搜索转为仅含发射日期和到达日期两个变量的寻优问题,引入小推力发动机的最大速度增量作为能量约束条件,将小推力运动学模型参数化,把各离散点的推力方向角和发动机的开关机时间作为优化参数,针对交会小行星的探测任务,设计优化目标和约束条件,采用罚函数设计相应的适应度函数。仿真结果表明:用遗传算法可快速获得与全局搜索一致的低能量星际转移窗口,同时小推力轨道控制优化结果不仅能满足相应探测任务的要求,还可提供更好的探测器终端状态约束。

The method to search for a low energy interplanetary transfer window and optimize the low thrust trajectory control based on genetic algorithm（GA）was studied in this paper.The low energy interplanetary transfer window was transferred into an optimization problem which only contained two variables of the launch date and the arrival date through the calculation of ephemeris and solving the Lambert problem.The maximum velocity increment which low thrust engines could achieve was introduced as an energy constraint.The low thrust kinematics model was parameterized.The thrust direction angles of each discrete point and the engine switch time were served as optimization parameters.For rendezvous asteroid probe mission,optimization objectives and constraints were designed and a penalty function was used to design appropriate fitness function.The simulation results showed that a low energy interplanetary transfer window could be quickly achieved based on GA,and the result of the optimized low thrust trajectory control would not only meet the requirements of the appropriate probe mission but also provide the better terminal state constraints.