未知控制方向的Bouc-Wen迟滞系统控制器设计

Controller design for Bouc-Wen hysteresis system with unknown control direction

在非线性系统中的迟滞特性和未知控制方向,会增大超调,增加不精确性,甚至影响系统稳定。针对一类具有未知常数和执行器非线性的迟滞系统,提出了一种自适应反步控制方案。首先,用Bouc-Wen模型来描述迟滞特性,并得到该微分方程的上界值;然后,采用Nussbaum函数来处理未知控制方向,采用误差变换使得跟踪误差限定在预设范围之内;最后,用自适应控制来减少非线性带来的振荡和超调。该方案中闭环系统的所有信号都是有界的,确保了系统暂态和稳态的性能。仿真结果表明该方案有效。

Hysteresis and unknown control direction in nonlinear system will increase overshoot and inaccuracy,even affecting system stability.An adaptive backstepping control scheme is proposed for a class of nonlinear hysteresis systems with unknown constant and actuator.Firstly,Bouc-Wen model is used to describe the hysteresis and the upper bound of differential equation is derived.Then,the unknown control direction is solved by Nussbaum function and error transformation is used to confine the error to a predefined residual.Finally,an adaptive approach is employed to reduce oscillation and overshoot caused by nonlinearity.All the signals in the closed-loop system are uniformly bounded and the controller ensures the transient and steady performance Simulation results show that this scheme is feasible.