Research On Sampling Period Problems And Event-Triggered Control Scheme For Networked Control System

Network control system is the research direction of academic hotspot in control field in recent years.In NCS,distributed closed loop control systems are formed by connecting the network nodes distributed in different physical areas through the real-time communication network.As a kind of distributed computer control system,there will be inevitably the signal sampling,maintenance and other issues in the system modeling,analysis and design of NCS.On the other hand,multiple loops are used to control in the way of sharing network communication resources,so it is quite important to control how to reduce the transmission of redundant information and improve the utilization of limited network bandwidth.In the analysis and design of the network control system,the selection of the sampling period can not only affect the control performance of the system,but also reflect the transmission of the data signal on the network.The current research results are mostly based on the method of fixed cycle sampling method,this way of sampling although conducive to modeling and simplify the system analysis,but not practical and even cause a waste of network resources.Taking into account the essential characteristics of network control system,this paper mainly includes the following two aspects:On the one hand,according to the time-varying characteristics of the data information in the communication network,the time-varying sampling period network control system is studied.There are two points in this work: Firstly,the 2L gain analysis of the variable-sampling periodic network control system with bounded time-varying delay is studied.The system is modeled as a discrete interval time-varying system,and the system state feedback controller is designed by using Lyapunov stability theory and linear matrix inequality technique.Secondly,for a class of multi-rate input sampling network control system,using the system's output predictive value,the dynamic output feedback controller is designed,and the optimal guaranteed cost control of the closed-loop system is studied.On the other hand,in order to overcome the shortcomings of periodic triggering,to avoid redundant information transmission in the network,to ensure the system performance while saving network communication resources,the event-triggered control scheme is studied in this paper.Considering the influence of packet losses and the network induced time delay,through the establishment of new mixed event-triggered control conditions and based on the output feedback control,the 2L gain analysis of the closed-loop system is studied by using linear matrix inequality technique and constructing a new Lyapunov-Krasovskii functional.