可逆冷带轧机速度张力系统的动态滑模解耦控制

Dynamic sliding mode decoupling control for speed and tension system of reversible cold strip mill

为削弱可逆冷带轧机速度张力系统中各变量间的非线性耦合影响,本文提出了一种基于幂指数趋近律的微分几何动态滑模解耦控制方法.首先,应用微分几何理论,通过非线性状态反馈和坐标变换,实现了可逆冷带轧机速度张力非线性耦合系统的输入/输出动态解耦和线性化.其次,针对解耦后得到的各独立线性子系统,综合考虑可逆冷带轧机速度张力系统的负载扰动、参数摄动和未建模动态等不确定部分的影响,基于幂指数趋近律设计了动态滑模控制器.理论分析表明,所提出的控制方法能够保证闭环系统渐近稳定,并能有效削弱系统抖振.最后,对某1422mm可逆冷带轧机速度张力非线性耦合系统进行仿真,并同其他解耦控制方法相比较,结果验证了所提出方法的有效性.

In order to reduce the nonlinear coupling influences among the variables in the speed and tension system of reversible cold strip mill, we propose a decoupling control strategy of differential geometry dynamic sliding mode based on the power exponential reaching law. Firstly, through nonlinear state feedback and coordinate transformation, a differential geometry theory is used to realize the input/output dynamic decoupling and linearization. Then, synthetically considering the load disturbance, parameter perturbation, unmodeled dynamics and other uncertainties, we design a dynamic sliding mode controller based on the power exponent reaching law for each of the independent linear subsystem. Theoretical analysis shows that the resulting closed-loop system is asymptotically stable, and the chattering is reduced effectively. A simulation is carried out on the speed and tension system of a 1422mm reversible cold strip mill. Results show the superiority of the proposed strategy in comparison with other decoupling control strategies.