一类不确定中立时变时滞系统的自适应全局滑模控制

Adaptive global sliding mode control for a class of uncertain neutral systems with time-varying-delay

针对一类含有时变状态时滞和中立时滞的不确定性系统,提出一种新型滑模变结构控制方法.首先,基于全程滑模的思想,设计带有中立时滞项的积分型滑模面以消除趋近模态;然后,充分利用时滞下界的信息选取Lyapunov函数,采用线性矩阵不等式(linear matrix inequality-LMI)方法给出并证明滑动模态稳定的充分条件,降低时滞保守性;再次,与自适应结合设计滑模控制器,采用饱和函数代替符号函数,削弱系统抖振;最后,针对数值算例进行仿真研究,结果表明所提出的控制方法有效可行.

This paper proposes a novel sliding mode control method for a class of uncertain systems with time-varying state delay and neutral delay.First of all,based on the global sliding mode control,a type of integral sliding surface with neutral time-delay is introduced to exhibits global robustness during the entire response.Then the Lyapunov function makes full use of the low bounds of time delay so that the conservative is lowered.In terms of the LMI,robust stable conclusions of sliding mode is proved.Fathemnore,an adaptive sliding mode controller is investigated and the system chattering is weaken by using the saturation function to replace the symbolic function.Finally,a numerical example is given to illustrate the applicability of the proposed method.