基于动态面的死区输入系统跟踪控制算法

Tracking Control Algorithm Based on Dynamic Surface for Nonlinear Systems with Dead-zone Input

针对具有未知死区输入的一类非线性严反馈系统,文中提出了一种基于动态面技术的自适应渐进跟踪控制策略。在处理虚拟控制器时,不同于传统动态面技术中采用的低阶滤波器,通过引入具有时变积分函数的非线性滤波器,不仅可以规避“微分爆炸”,降低计算负担,简化控制器,还可以很好地补偿动态面方法引起的边界层误差。理论分析证明,所提出的控制方案能够消除死区非线性的影响,保证闭环系统的稳定性。以单力臂机械手的仿真为例,通过调节设计参数去提高系统的瞬态跟踪性能,实现了系统跟踪误差渐进收敛,验证了所提出控制策略的有效性。

The adaptive dynamic surface control is proposed for a class of uncertain nonlinear strict-feedback systems proceeded by unknown input dead-zone.Unlike the low-order filters used in CSCD,the nonlinear filters with time-varying integral function are utilized to cope with the virtual controls.The proposed control method not only overcomes the“explosion of terms”and reduces the computational complexity,but also simplify the structure of the controller.Furthermore,it compensates the boundary layer error inherent in the dynamic surface procedure.Theoretical analysis proves that the proposed control scheme can eliminate the influence of dead zone nonlinearity and ensure the stability of the closed-loop system.Taking the simulation of a single-arm manipulator as an example,the transient performance can be improved by the tuning of design parameters,and the asymptotic convergence of the tracking error can be achieved,which verifies the effectiveness of the proposed method.