基于复合干扰观测器的CMG框架系统高精度转速控制

High Precision Gimbal Speed Control for CMG via Composite Disturbance Observer

为使控制力矩陀螺(CMG)输出高精度力矩,框架转速必须具有足够高的控制精度.然而,在CMG框架伺服系统中,存在转子动不平衡力矩,齿槽力矩,电流脉动,非线性摩擦等多种干扰,严重影响了框架控制性能.为抑制各种干扰对框架控制性能的影响,文章设计了一种基于复合干扰观测器的非线性鲁棒控制器.首先,将系统中存在的干扰模化为频率已知的周期性干扰和变化率有界的慢变干扰,建立了三阶干扰动态模型,设计了复合干扰观测器,从而实现了对复杂干扰的准确估计.在此基础上,采用backstepping方法设计了框架转速非线性鲁棒控制器,实现系统的反馈控制.针对某CMG框架系统的转速控制仿真表明,该方法是可行的.

High precision speed control performance of the control moment gyro(CMG)gimbal system is one of the essential factors that determinate the output torque accuracy of the CMG.However,there are multiple disturbances seriously deteriorate the CMG gimbal speed control performance in the servo system,such as the dynamic imbalance torque,cogging torque,current fluctuations and nonlinear friction torque.To attenuate the disturbances and achieve high precision speed control of CMG gimbal,a composite disturbance observer(CDO)based nonlinear robust controller is designed in this paper.Firstly,a third-order model of disturbances is built which modeling the differential bounded disturbance torque and dynamic unbalance periodic disturbance torque respectively.Then a composite disturbance observer is designed for disturbances estimation and feedforward compensation.On the basis of this,a nonlinear robust controller is designed based on backstepping method for feedback control of the servo system.In the end,simulation results of a CMG gimbal servo system verify the effectiveness of the designed controller.