状态约束下连铸结晶器振动位移系统的抗干扰控制

Disturbance rejection control for continuous casting mold vibration displacement system with states constraints

中文关键词  连铸结晶器  状态约束  切换函数  扩张状态观测器  滑模控制

英文关键词  Continuous casting mold, State constraints, Switching function, Extended states observer, Sliding mode control

中文摘要

      针对伺服电机驱动的连铸结晶器振动位移系统中存在的机械加工精度误差、摩擦非线性等不确定性和负载转矩扰动等问题，考虑伺服电机单方向变速转动产生的状态约束，提出了一种基于切换函数的抗干扰控制方案。首先，针对系统中状态约束且不可测及前向通道含有非线性周期函数（近似正弦函数，逆解非唯一）传递关系的问题，通过建立偏心轴转角误差与结晶器振动位移之间的函数关系，解决系统自身的状态约束问题。其次，针对系统存在的不确定性和负载转矩扰动问题，设计切换函数重构系统中存在的整体不确定性，通过扩张状态观测器对整体不确定性进行估计，将估计值与滑模控制方法相结合设计输出反馈控制器，实现结晶器振动位移的跟踪控制。最后，通过Lyapunov理论证明了控制系统的稳定性，通过仿真验证了本文所提方法的有效性。

英文摘要

      With the continuous casting mold vibration displacement system driven by servo motor as the research object, in view of the system uncertainties, such as the machining error of reduction ratio and friction nonlinear, and the load torque disturbance and the constrained states caused by the servo motor rotated with variable speed rotation and single direction , an disturbance rejection control method based on the switching function is proposed. Firstly, for the system states constraints with immeasurability and the transfer relationship with nonlinear period function(approximate sine function with non-unique inverse solution) in the forward channel, the correspondence function between the eccentric shaft angle error and the displacement of the mold is established to deal with the states constraints. Secondly, for the system uncertainties and the load torque disturbances, the switching function is designed to reconstruct the total system uncertainties, which is estimated by the designed the extended states observer(ESO). The output-feedback controller is proposed based on the uncertainties estimated value and the sliding mode method to realize the mold displacement tracking control. Finally, the system stability is demonstrated through Lyapunov theory and the simulation results show the effectiveness of proposed control scheme.