基于扰动观测器的双容水箱液位系统自适应滑模控制

Adaptive Sliding Mode Control of Two-tank Liquid Level System Based on Disturbance Observer

针对存在外部扰动的双容水箱液位系统,为了实现精确的液位控制,该文提出了一种基于非线性扰动观测器的自适应滑模控制方法。设计了含积分作用的滑模面和自适应滑模趋近律,以提高趋近速度和控制精度,并且减小抖振。同时提出了一种非线性扰动观测器估计系统的外部扰动,并将估计值前馈补偿到自适应滑模控制器。通过李亚普诺夫稳定性定理证明了该控制策略的闭环系统稳定性。仿真和实验结果表明,在系统存在外部干扰的环境下,所提出的控制策略与传统滑模控制方法相比,控制精度更高且干扰抑制能力更强。

An adaptive sliding mode control method based on nonlinear disturbance observer is proposed for the accurate liquid level control of the two-tank liquid level system with external disturbance.A sliding mode surface with integral action and an adaptive sliding mode reaching law are designed to improve the approach speed and control accuracy and reduce chattering.At the same time,the nonlinear disturbance observer is proposed to estimate the external disturbance of the system,and the estimated value is fed forward to the adaptive sliding mode controller.The closed-loop system stability of the control strategy is proved by Lyapunov theorem of stability.The simulation and experimental results show that the proposed control strategy has higher control precision and better disturbance suppression ability than the traditional sliding mode control method in the environment with external disturbance.