基于Lyapunov-Elman的网络控制系统时延预测方法

Abstract

The time-delay in the networked control system is an important parameter affecting the performance of a system. A maximum Lyapunov exponent and Elman neural network prediction method is presented according to the time-delay prediction in the networked control system based on the Internet. Firstly, time-delay sequences are reconstructed by phase space reconstruction, embedding dimension and time delayed variable is obtained. Then one step time-delay is forecasted by maximum Lyapunov exponent and Elman neural network. A final time delay prediction value is obtained after two prediction methods are multiplied by different weight coefficients. Finally, based on the weight coefficient optimization, this paper presents an improved free search algorithm, whose convergence accuracy and speed are superior to those of the standard free search algorithm. Simulation results show that, time-delay prediction method based on maximum Lyapunov exponent and Elman neural network in the paper has higher prediction accuracy and smaller prediction error than other prediction methods.