双框架控制力矩陀螺框架系统的扰动观测及抑制

Disturbance observation and rejection for gimbal system of double gimbal control moment gyroscope

内外框架间的耦合力矩、非线性摩擦和未建模动态是影响双框架控制力矩陀螺框架系统高精度角速率伺服控制的主要因素。为提高框架系统的干扰抑制能力,保证框架系统输出角速率精度,本文提出了一种基于非线性级联扩张状态观测器和滑模控制的复合扰动抑制方法。框架系统中的所有干扰都被认为是集总干扰并由设计的NCESO估计,通过滑模控制可从系统输出通道中消除集总干扰的影响。最后,将本文提出的控制方法与线性级联扩张状态观测器和状态反馈结合的复合控制方法进行了对比仿真实验。仿真和实验结果表明,本文提出的方法具有更好的干扰抑制和动态响应性能,内框架角速度波动从0.5(°)/s减小到0.2(°)/s,外框架角速度波动从0.45(°)/s减小到0.15(°)/s;跟踪正弦参考信号时,速度跟踪误差从1.8(°)/s减小到1.2(°)/s,相位滞后从8°减小到1.3°。

Coupling moments,nonlinear friction,and unmodeled dynamics between inner and outer gimbals are the main factors that influence the precise control of a double gimbal control moment gyro(DGCMG).To improve the interference suppression ability and ensure the output angular speed accuracy of gimbal systems,this study presents a composite decoupling control method based on a nonlinear cascade extended state observer(NCESO)and sliding mode control.All disturbances in a gimbal system are regarded as the lumped disturbance,which is estimated by the designed NCESO.By combining a sliding mode controller,these disturbances can be eliminated from the output channel of the system.Finally,simulations and experiments of the control method proposed in this study and a linear cascade extended state observer(LCESO)combined with state feedback were carried out.The simulation and experimental results show that the proposed method has better interference suppression performance and dynamic response performance.The angular speed fluctuation of the inner gimbal is reduced from 0.5(°)/s to 0.2(°)/s and the angular speed fluctuation of the outer gimbal is reduced from 0.45(°)/s to 0.15(°)/s.Moreover,the speed tracking error is reduced from 1.8(°)/s to 1.2(°)/s and the phase delay is reduced from 8°to 1.3°when tracking the sinusoidal reference signal.