一类非线性大滞后系统自适应积分滑模控制

针对一类非线性大滞后系统, 基于伪偏导数概念的动态线性化非线性系统模型, 利用离散时间预测器技术, 实现了系统原始表达式中滞后环节的隐性表达, 并结合离散积分滑模控制(discrete integral sliding mode control, DISMC)方法, 提出了一种新的无模型自适应离散积分滑模控制(model-free adaptive discrete integral sliding mode control, MFA-DISMC)方案. 该方法的主要特点是控制器设计仅取决于被控对象的输入和输出测量数据. 通过理论分析证明了算法的稳定性, 仿真研究表明, 相比于无模型自适应控制(model-free adaptive control, MFAC)、Smith预估控制、改进的MFAC控制以及比例–积分–微分(proportional-integral-derivative, PID) 控制方法, 本文方法具有更快的响应速度和更强的鲁棒性. 最后, 通过双容水箱液位控制系统的实验研究, 验证了所提出方法的有效性.

An adaptive integral sliding mode control for a class of nonlinear large-lag systems

For a class of nonlinear large-lag systems, the pseudo-partial-derivative is used to dynamically linearize the nonlinear system model, and the predictor in discrete time is applied to converts the original system with input delay to an equivalent system without the explicit appearance of time delay. Then, combined with discrete integral sliding mode control (DISMC) method, a new model-free adaptive DISMC (MFA-DISMC) algorithm is presented. The main feature of the approach is that the controller design depends merely on the input and the output measurement data of the controlled plant. Moreover, theoretical analysis proves the stability of the proposed algorithm. Simulation studies show that the proposed method has faster response speed and stronger robustness than model free adaptive control (MFAC), Smith predictive control, improved MFAC and proportion integration differentiation (PID) control method. Finally, the effectiveness of the proposed approach are validated through the practical two-tank water level control system.