网络控制系统中在线时延测量及时延补偿

为了克服网络控制系统中随机时延对控制性能产生的影响,提出了基于在线时延测量和一步预测输出(基于在线参数辨识)的随机时延补偿方法。通过对以太网中随机时延的分析,提出一种在以太网中不存在同步时钟的情况下在线测量时延的方法;在在线辨识模型参数基础上,得到对象一步(随机时延小于一个采样周期)预测输出,从而根据测得的时延得到对象由于随机时延而引起的输出量变化;再用变化量加上对象输出量用于控制算法反馈。最后通过基于以太网控制实验平台对液位对象进行控制所得的结果,验证了时延测量方法和随机时延补偿算法的有效性。

Stochastic Time Delay Compensation for Networked Control Systems Based on Online Delay- measurement

In order to overcome the adverse influences of the stochastic network-induced delay in the networked control systems,a novel stochas- tic time delay compensation strategy is presented based on an online delay-measurement and one-step predictive output with parameter identifica- tion.By analyzing the constitution of stochastic delay in the Ethemet,an online delay-measurement approach is proposed in the absence of any synchronized clock.Integrated with the measured delays and the parameter identification,the one-step predictive output can be obtained to pre- dict the output variation of the plant caused by the time delay,and the predictive output can he used to compensate stochastic time delay.The ef- fectiveness and performance of the compensation are demonstrated by a single tank level control.