Abstract: In order to model and estimate random communication time delay in Networked Control Systems（NCS）,a six months’ latency test,based on IETF’s（Internet Engineering Task Force） RFC2544,has been performed with an application layer based test software.More than 1.7 million data have been obtained for correlation analysis.An adaptive autoregressive（AR） model and a Least Mean Square（LMS） adaptive algorithm is used for the time delay estimate and prediction.Experimental results show that the proposed method has good performance in time delay prediction of networked control systems.

Key words: Networked Control Systems, time delay estimation, latency test, RFC2544, adaptive AR model, adaptive LMS algorithm

摘要： 针对网络化控制系统（NCS）中的随机时变时延,采用自行开发的基于应用层的测试软件,按照IETF（The Internet Engineering Task Force）的RFC2544规范,进行了6个多月实际测量,获得了170余万个网络时延数据;通过对实验数据进行相关分析,建立了网络时延的自适应自回归（AR）模型;并用自适应最小均方差（LMS）算法对实测的网络时延进行了估计和预测,实验结果表明了算法的有效性。

关键词: 网络化控制系统, 时延估计, 网络时延测试, RFC2544, 自适应AR模型, 自适应LMS算法