Abstract: This paper integrates model including the non-ideal network conditions such as network-induced delay，data packet dropout and wrong-sequence is proposed when considering the total factors of Networked Control Systems（NCSs）.Based on this model，the H_∞ performance analysis and the H_∞ controller design are obtained for the closed-loop NCSs.Besause of the adoption of new analytical method of the time-delay system and the consideration of the lower bound of the network-induced delay，the designed H_∞ controller has less conservativeness and extensive applicability.Finally，a simulation example is provided to show the availability of the proposed approach.

Key words: Networked Control Systems（NCSs）, sampled-data system, time-delay system, Linear Matrix Inequality（LMI）, H_∞ controller

摘要： 针对网络控制系统的主要影响因素，建立包含网络诱导时延和数据丢包及错序等非理想网络状况的系统统一模型。以此为基础，对闭环网络控制系统进行了H_∞性能分析和H_∞控制器设计。由于采用新的时滞系统分析方法并考虑网络诱导时延的下界大于零这一事实，所设计的控制器具有较小的保守性和广泛的适应性。最后通过仿真例子，表明所得结果的正确性。

关键词: 网络控制系统, 采样系统, 时滞系统, 线性矩阵不等式, H_∞控制器