Abstract: The design approach of robust H_∞ controller for Network Control System（NCS） with random time-delay is studied in this paper.The model problem is discussed firstly.With time-driven sensor and event-driven controller and actuator，supposing that the time-delay is less than one sampling period，the NCS is modeled as an uncertain discrete linear system with delay，based on the Lyapunov functional approach and Linear Matrix Inequality（LMI） formulation；sufficient condition of asymptotic stability and H_∞ norm less than performance index γ is derived.And H_∞ control law design methods for dynamical output feedback are presented.A numerical simulation example with Matlab shows that the design method is effective.

Key words: Network Control System（NCS）, random time-delay, H_∞ control, dynamic output feedback

摘要： 研究了存在不确定时延的网络控制系统的鲁棒H_∞控制器设计方法。首先讨论了系统的建模问题，针对传感器采用时间驱动，控制器和执行器采用事件驱动，考虑不确定时延小于一个采样周期的情况，网络控制系统可建模为一类具有不确定性的线性离散时延系统，利用Lyapunov方法和线性矩阵不等式方法，推导出闭环控制系统渐近稳定且H_∞范数小于性能指标γ的充分条件，并给出动态输出反馈H_∞控制律设计方法。通过Matlab数值仿真，证明了该设计方法的有效性。

关键词: 网络控制系统, 不确定时延, H_∞控制, 动态输出反馈