含死区高阶非线性系统自抗扰动态面控制
Active disturbance rejection dynamic surface control of high-order nonlinear system with dead-zone

针对一类含有未知死区输入的不确定纯反馈非线性系统, 为实现精准控制, 提出一种新的基于扩展状态观 测器的动态面控制算法. 用扩张状态观测器代替函数逼近器在线估计高阶系统动态面控制中每一步的不确定函数. 结果表明, 估计误差显著降低, 闭环控制性能得到实质性改善. 此外, 设计跟踪微分器来消除传统反推方案中计算 复杂的问题. 通过李雅普诺夫方法分析了具有自适应鲁棒控制器的闭环系统的稳定性. 最后, 对所提出的自适应鲁 棒控制方案进行仿真, 取得了满意的结果.
For a class of uncertain nonlinear systems in pure-feedback form, preceded by unknown dead-zone, a new dynamic surface control (DSC) algorithm is proposed to achieve precise control. Instead of using function approximators, extended state observers (ESO) are employed to online estimate uncertain functions in each step of DSC. As a result, the approximation error is significantly reduced and the closed-loop control performance is essentially improved. In addition, tracking differentiator (TD) is designed to eliminate “explosion of complexity” in traditional backstepping scheme. Stability analysis of the whole closed-loop system is analyzed by Lyapunov method, in which the adaptive robust controller is designed. Finally, examples are simulated under the proposed adaptive robust control method with satisfactory results