基于路径规划的敏捷卫星姿态机动反馈控制方法

Feedback control method for attitude maneuver of agile satellite based on trajectory optimization

为了避免奇异状态,单框架控制力矩陀螺(SGCMG)操纵律要求框架角进行快速转动,需要消耗较多的能量,并会对SGCMG和卫星系统带来一系列潜在危害。针对该问题,提出基于路径规划和反馈控制相结合的姿态机动控制方法。根据固定时间姿态机动的任务需求,以能量为优化指标,采用伪谱法优化机动路径并回避奇异状态;将最优控制量作为参考数输入,并利用基于系统限制状态的反馈控制方法消除不确定性和扰动的影响。反馈控制基于名义输入进行数值积分得到的预测状态量,并与期望终端状态比较形成控制误差信号。该方法将卫星和SGCMG作为整体规划姿态运动,能够有效避免奇异状态。结合工程实际,在闭环控制仿真中考虑了卫星角速度和SGCMG框架角的初始偏差。仿真结果表明:本文算法能够有限避免奇异状态,且能消除初始姿态角速度和框架角不确定的影响。

Rapid actuation is needed to avoid singularity state in the single-gimbal control moment gyros （SGCMG） steering logic. It consumes significant energy and produces danger for system. A novel control method for attitude maneuver combined trajectory and feedback control is proposed. Firstly, to avoid the singnlarity state, the pseudospectral method was used to solve the energy optimization issue. Then optimal solution of control acted as reference input, and feedback control method based on the system~ limit state was used to consider the effect of uncertainty and disturbances. Feedback control predicted the state based on the numerical integration of reference input, and the error was based on the comparison of the designed state and the predicted state. Numerical simulation was carried out to verify the feasibility of the proposed method, which shows that it can avoid the singularity state, and is valid to overcome the error of the initial velocity of satellite and gimbal angular of SGCMGs.