This paper rigorously investigates the problem of active disturbance rejection control for nonlinear systems subject to uncertainties and dead-zone input. One of the features of the considered systems is that the dead-zone parameters are allowed to be time varying and asymmetrical. The main idea of this paper is to utilize an extended state observer (ESO) to estimate all the external disturbance, the uncertain nonlinearity, the unknown dead-zone model, and the unmeasurable states. A switched dynamic parameter estimation law is established to separate the dead-zone model from the total uncertainty and estimate the parameters of dead-zone online. Based on the proposed estimation law and the ESO, an output feedback linearization control law is designed to cancel the total disturbance and compensate the dead zone. The theoretical analysis of stability shows that the closed-loop system has multi-time scale convergence properties. Finally, simulation results are provided to illustrate the efficiency of the proposed method.

中文翻译：

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具有未知时变死区输入的不确定非线性系统的自抗扰自适应控制

本文严格研究了受不确定性和死区输入影响的非线性系统的主动抗扰控制问题。所考虑系统的特征之一是允许死区参数随时间变化和不对称。本文的主要思想是利用扩展状态观测器 (ESO) 来估计所有外部干扰、不确定非线性、未知死区模型和不可测量状态。建立切换动态参数估计律，将死区模型与总不确定性分离，在线估计死区参数。基于所提出的估计律和ESO，设计了输出反馈线性化控制律，以消除总扰动并补偿死区。稳定性理论分析表明，闭环系统具有多时间尺度收敛性。最后，仿真结果说明了所提方法的有效性。