Real-time Communication Method Of Cyber-physical Systems Based On Complex Networks Analysis

Cyber-physical systems is an intelligent system that deeply organically integrates information technology,physical equipment,and environment.Real-time interaction is one of the important characteristics of cyber-physcical systems.Good real-time performance significantly improves the network space performance of the systems,and a large network delay may have a devastating impact on the systems,such as failure to handle real-time environment in time,etc.,causing the systems to crash.With the introduction of Industry 4.0,all walk of life around the world attach great importance to various aspects of research work with cyber-physcial systems as the core technology.The research on real-time communication of cyber-physical systems has always been a research hotspot in this field.This thesis proposes a real-time communication method for the cyber-physcial systems because the existing traditional routing algorithms cannot quickly adapt to the network communication requirements of the surge in physical facilities.This method abstracts the physical network nodes of the cyber-physical systems into a complex network diagram,and builds an overlay nertwork that can ignore the complex topology of the physical layer the traditional IP routing through virtual logical links Address link,and then use the intelligent optimization algorithm to seatch for the optimal coverage node set,so that the cyber-physical systems established by the optimal node set minimizes the overall communication of the cyber-physcial systems.The main research contents of this thesis are as follows:(1)An overlay network construction model based on the shortest route path is proposed based on a complex network.The most important thing to build an overlay network is the selection of the overly node set.The NP-hard analysis of the objective function of the overlay node set proves the choice of the overlay node set it is an NP complete problem.(2)The selection strategy of covering node set can be realized by optimization algorithm,and an improved meta-heuristic intelligent optimization algorithm is proposed.Combining the characteristics of the overlay network structure model of the cyber-physcial systems,the neighborhood structure and shaking method of the variable neighbothood search algorithm are improved,and a decreasing variable neighborhood descent method is proposed and another set of solutions is randomly initialized to jump out of the current the jitter mode of the search path.The proposed method simplifies the algorithm structure and reduces the calculation time of the algorithm while searching for the global optimal value by transforming different neighborhoods.(3)The above models and algorithms are simulated on MATLAB.The experimental results show that the overlay network model and the impoved variable neighborhood search algorithm proposed in this thesis are effective to the optimal selection strategy of the overlay node set,and gice the 95% confidence interval of the experimental results shows that the method has good robustness and verifies the feasibility of the proposed communication method to effectively reduce the network delay.(4)Taking into account the characteristics of the complex topology of the complex network,the data set with a large number of nodes is clustered by k-means,the large scale network is divided into several subnets,and the method proposed in this thesis is used to construct sub-covers for each subnet.The network is connected to each other through suboverlay networks to form an overall overlay network,further optimizing the real-time communication method of the cyber-physical system.The simulation experiment results show that selecting the appropriate number of clusters and the number overlay nodes can further reduce the network delay.