Research On Security Control Of Networked Systems Based On Event-triggered Sliding Mode

With the rapid development of communication networks,computer technology and control theory,networked control systems(NCSs)have been widely used in intelligent buildings,smart grids,and other fields.NCSs are a kind of spatially distributed system.Each component in the system relies on the communication network to share data.Therefore,NCSs have incomparable advantages over traditional control systems,such as high system flexibility and low maintenance cost.However,the introduction of communication networks also brings many challenges to NCSs.Network-induced phenomena,such as data packet loss,data transmission delay,and quantization error caused by data quantization,will affect the performance of the system and even lead to system instability.In particular,due to the openness of the communication network,data is vulnerable to network attacks during transmission.Aiming at the problem of limited network resources and security control in NCSs,this thesis introduces event-triggered mechanism and sliding mode control and studies the security control of networked systems based on event-triggered sliding mode.The main contents of this thesis are as follows:(1)The master-slave synchronization control problem of delayed neural networks(DNNs)based on adaptive event-triggered global sliding mode under deception attacks is studied.Aiming at the problem of limited network resources in NCSs,an adaptive event-triggered mechanism(AETM)is introduced to save network bandwidth.Considering the diversity of deception attacks,a new deception attacks model is constructed by using a set of random variables satisfying Bernoulli distribution and two different deception attacks.To make the system have global robustness,a new sliding surface(SS)is constructed and a sliding mode controller is designed.Then,by constructing the Lyapunov functional,sufficient conditions for the master-slave synchronization of DNNs are given in the form of linear matrix inequality(LMI).Finally,the feasibility of the proposed method is verified by a numerical example.(2)A global sliding mode control(GSMC)strategy based on adaptive event-triggered is proposed for NCSs with input constraints and deception attacks.Due to the openness of the network,the data is considered to be subject to deception attacks during transmission.Then a new SS is designed based on AETM with input constraints,which eliminates the arrival stage in SMC and makes the system robust in the whole stage of response,and the mathematical model of the closed-loop system is constructed.Then,by using Lyapunov functional and LMI techniques,sufficient conditions for the stability and performance of the closed-loop system are obtained.Finally,the effectiveness of the method is verified by numerical simulation.(3)The master-slave synchronization control problem of DNNs based on adaptive event-triggered global sliding mode under duel-ended hybrid cyber-attacks is studied.Firstly,considering the uncertainty of the system structure and the unmodeled dynamics of the system,the mathematical models of the master-slave delayed neural networks and the error system are constructed.Then,the controlled object,AETM,input constraint,duel-ended hybrid cyber-attacks,and global sliding mode controller are incorporated into a unified framework,and the mathematical model of the switched system is established.Among them,deception attacks and replay attacks are considered at the sensor-to-controller(S-C)end.On the Controller-to-Actuator(C-A)end,the Denial-of-Service(Do S)attacks are considered.Then,combined with the piecewise Lyapunov functional method,sufficient conditions are obtained to ensure the Exponentially Mean Square Stable(EMSS)of the switched system.Finally,the effectiveness of the method is proved by numerical examples.