基于近似动态规划的三轴卫星姿态最优控制

Abstract

应用近似动态规划方法解决三轴卫星姿态最优轨迹规划问题，首先使用三轴卫星的动力学和运动学模型，对于给定的始末姿态，选取姿态机动能量消耗最少作为待优化的性能指标。文中根据自适应动态规划结构，分别利用评价网络来近似性能指标函数和执行网络来逼近控制变量，龙格库塔法求解状态变量，并给出了适合该类问题的一种效用函数的具体表达式。仿真结果表明应用近似动态规划解得的三轴卫星最优轨迹，能够较好地满足各种约束条件，而且计算精度高、速度快，具有很好的实时性。 The optimal attitude trajectory planning of three-axis satellite using approximate dynamic pro-gramming (ADP) method is discussed. Firstly, the dynamic and kinematic equations of the three-axis satellite are used, and for given initial and final attitudes, the performance to be opti-mized is selected as minimizing the rest-to-rest maneuver energy. On grounds of adaptive dynamic programming structure, critic network and action network are used to approximate performance index function and control variables respectively, and Runge-Kutta method to solve the state variables. Besides, a concrete expression of the utility function is provided which is suitable for this kind of problem. The simulation results show that the proposed algorithm satisfies the constraints well and can be used on-line with its small computational amount and low computational complexity.