Stability And Stabilization Analysis Of Stochastic Networked Control System With Time Delay

It is undeniable that although the network control system has many advantages,there are various uncertain factors,such as random interference in the external environment,network delay,packet loss,network attacks in the internal environment,etc.In addition,there are many nodes in the large-scale network control system.Under the limited resources of network bandwidth,the amount of data and instructions needed to be exchanged is huge,which makes the network control system often appear network congestion phenomenon,and at the same time causes excessive calculation of the controller.Therefore,it is of great significance to study the random interference,network time delay and reduce the waste of network resources.At the same time,the combination of network communication and control technology makes the design and analysis of control system more complex,which also brings new challenges to control theory.For above problems,this paper studies the stochastic networked control system with network time delay,including stability analysis,control synthesis and design of transmission triggering mechanism.The main research contents and innovations of this paper are as follows:(1)In order to be closer to the actual system,this paper studies the robust control of stochastic networked control systems with multiple time delays and additive time-varying delays.Different from other papers,this paper first considers both the state delay of the controlled object and the network induced delay in the process of network transmission.By constructing a suitable Lyapunov-Krasovskii functional and using the improved free weight matrix method,a less conservative stability criterion is obtained;and the controller gain is obtained by solving linear matrix inequality.It can be concluded from the simulation example that the upper bound of network delay obtained by this system is higher than other related articles.It can also be seen from the trajectory of state motion that the stability of the system is better.(2)In this paper,a semi Markov jump network control system model with time-delay and actuator fault is established.Under the introduction of an improved event triggering mechanism,the system stability analysis and controller design are carried out.In order to reduce the conservatism of the upper bound of delay,this paper employs Bessel-Legendre inequality method,and establishes a new suitable Lyapunov-Krasovskii functional related to Legendre polynomial matrix,and obtains the stability criterion with lower conservatism.This stability criterion is associated to the order of Legendre polynomial matrix,and the conservatism will decrease with the increase of the order.In addition,the designed event triggering mechanism can not only effectively reduce the number of triggering,reduce the network burden,but also make the system automatically have a higher trigger frequency in the initial period of time,gradually reduce the trigger frequency in the process of approaching the steady state,so as to speed up the dynamic process.(3)Consider the existence of network attack in stochastic networked control system.The studied network attack is deception attack.Under this condition,an improved distributed event-triggered mechanism is designed,and the investigation of stability and stabilization is completed.