基于鲁棒状态观测器的运载火箭姿态控制系统设计

考虑弹性振动和液体晃动,采用鲁棒观测器设计了运载火箭的姿态控制系统。将姿态角测量结果中弹性振动的影响视为外界干扰,利用状态观测器的低通滤波特性实现对高频弹性信号的衰减,同时状态观测器替代速率陀螺估计得到姿态角速度,以姿态角和角速度信号为输入,采用扭曲二阶滑模控制方法设计了姿态控制律,并从理论上对该控制律稳定液体晃动和弹性振动的原理进行了证明,对观测器变换矩阵的选择进行分析。数值仿真表明,在参数摄动和干扰的影响下,所提出的变结构控制律能够有效的跟踪控制指令,稳定系统姿态,具有较强的鲁棒性,同时鲁棒状态观测器能够准确的估计出角速度信息。

Attitude Control for Launchers Based on Robust State Observers

Regarding the bending and sloshing modes,the attitude control system of a launcher is designed by means of using robust state observers.The signal introduced by flexible modes is regarded as disturbance.On account of low pass characteristics of the state observer,the high frequency modes can be attenuated.The attitude rate is reconstructed by applying the state observer,and then the rate gyroscope is unnecessary.By using second-order super-twisting sliding mode control,the control system is built based on the attitude angle and angle rate.The stability of bending and sloshing modes is proved theoretically.The numerical simulation indicates that the commands can be tracked effectively in the flight control system and the attitude can be stabilized with fairly robust.Meanwhile,the observer can estimate the rate of angle exactly.