一种偏置动量轮在轨维护的变带宽控制方法

针对长寿命运行卫星在轨维护中出现的备份偏置动量轮离散性差异较大,导致俯仰角收敛缓慢的问题,在姿态现象分析的基础上,根据卫星姿态动力学原理,建立偏置动量轮工作模式下的俯仰姿态的PID(Proportion Integration Differentiation,比例积分微分)控制模型,并进行系统开环与闭环传递函数公式推导。然后在伯德图(Bode Diagram)基础上,重点分析相位裕量的敏感参数,给出俯仰姿态控制回路的带宽调整方法,实现变带宽控制。卫星偏置动量轮在轨切换维护的结果表明,通过及时调整PID参数,减小回路带宽,可以有效改善相位裕量,保持卫星控制性能,实现俯仰姿态快速收敛,且俯仰角控制精度优于0.03°,取得较好的应用效果。

Adjusting Bandwidth Control for In-Orbit Maintenance of Biased Momentum Wheels

To solve the problem of slow convergence of pitch attitude of long lifetime satellites during in-orbit maintenance due to disparity of discreteness of the backup biased momentum wheel,a PID (Proportion Integration Differentiation) control model is established for pitch and attitude in biased momentum wheel operation mode based on satellite attitude dynamics following analysis of attitude phenomena.Open-loop and closed-loop transfer functions are derived.The sensitive parameters of phase margin are analyzed with Bode diagram and a changeable bandwidth control method is given for the pitch attitude control loop.The results have shown that,by adjusting PID parameters in loop to narrow control bandwidth,phase margin is improved and it is better to get a rapid convergence for pitch attitude with a precision lower than 0.03 degrees to keep normal working performance for long lifetime satellites.