针对伺服电机驱动的连铸结晶器振动位移系统中存在减速器齿轮间隙和偏心轴机械零位偏移等问题,提出了一种基于干扰观测器的反步滑模控制方法。首先,针对减速器齿轮间隙和偏心轴机械零位偏移等扰动不确定项以及负载扰动,采用干扰观测器对其构成的复合干扰进行逼近估计,使观测误差在有限时间收敛,并将观测值动态补偿到控制器中,提高了系统的控制精确度;其次,基于反步法完成位移系统动态滑模控制器的设计,提高了系统状态的收敛速度,增强了系统的鲁棒性。仿真结果表明,所设计的干扰观测器能够准确、快速的估计出系统存在的干扰及负载转矩,且位移控制系统能够实现位移的渐近跟踪控制。
Aiming at the problems of reducer gear clearance and the deviation of the eccentric shaft mechanical zero offset, which exist in displacement system of the continuous casting mold driven by servo motor, a backstepping sliding mode controller based on disturbance observer is designed. Firstly, For the reducer gear clearance and eccentric shaft mechanical zero offset disturbance uncertainties and load dis- turbances, disturbance observer was adopted to approximatly estimate the compound disturbance. The ob- servation error in finite time convergence, and the observed value dynamic compensation to the controller, it can improve the control precision of the system was improved. Secondly, using backstepping method to design the displacement system dynamic sliding mode controller, which improves the convergence rate of the system state, and enhances the robustness of the system. The simulation results show that observer esti- mate the system interference and load torque quickly and accurately, and the displacement control system can track the given signal.