基于非奇异快速终端滑模的轧机液压伺服位置系统反步控制

针对具有非线性、参数不确定性和未知负载扰动的非对称缸轧机液压伺服位置系统,提出一种基于模糊自适应观测器和非奇异快速终端滑模面的反步控制方法.首先,基于非奇异快速终端滑模面和双幂次趋近律完成非对称缸轧机液压伺服位置系统反步控制器的设计,并通过构造二阶滑模滤波器对虚拟控制量的微分信号进行估计,有效地避免了反步控制中的微分爆炸现象;然后,选用模糊自适应观测器对系统的不确定项进行逼近估计,并将输出的估计值引入到设计的控制器中进行补偿,有效地提高了系统的跟踪控制精度,且分析表明,所提出的控制方法能够保证闭环系统全局渐近稳定;最后,基于某650mm可逆冷带轧机液压伺服位置系统的实际参数进行仿真研究,并与常规线性滑模控制方法相比较,结果验证了所提出方法能够有效提高系统在整个全局过程的收敛速度和鲁棒稳定性.

Backstepping control of rolling mill hydraulic servo position system based on nonsingular fast terminal sliding mode

Aiming at the hydraulic servo position system for asymmetric cylinder rolling mill with nonlinearity, parameter uncertainty and unknown load, a compound control algorithm is designed based on the fuzzy adaptive observer and non singular fast terminal sliding mode in this paper. Firstly, the a backstepping controller is designed based on the non singular fast terminal sliding mode and double power reaching law, and second-order sliding mode filters are constructed to estimate the differential signals of the virtual controls, which can avoid the differential explosion during using the backstepping control effectively. Then, fuzzy adaptive observers are used to approximate the uncertain items in the designed controllers, so as to improve the control precision of the system. Theoretical analysis shows that the closed-loop system is globally asymptotically stable. Finally, simulation is carried out by using the actual data of the hydraulic servo position system of a 650mm reversing cold rolling mill, and the results show that the proposed control method can enhance the asymptotic tracking performance and robust stability of the system in the whole global process through comparing with the conventional sliding mode control method.