Event-Triggered H_? Filtering Over Networked Systems Under DoS Jamming Attacks

Nowadays,computer science and technology,network communication technology and control science and theory are becoming more and more mature.Networked control systems built by network communication technology are gradually being applied in large industries.Networked control system uses a communication network to connect controlled objects such as sensors,controllers,filters and actuators in the system to form a closed-loop system.The advantages of networked systems are:lower cost,easier installation,easier maintenance,and higher performance.However,when network communication technology is applied to large-scale industries,there are also some traditional network problems,such as limited channel resources,network attacks,transmission delays,and packet loss,which may result in system performance degradation.Therefore,solving the problems of channel resource limitation and network attack and improving the performance of the networked system has great development prospects and practical application value.This paper studies the problem of networked system filter design based on attack.Although the filter technology in the networked system has achieved certain results,there are still some shortcomings:Firstly,the proposed filter design method is basically aimed at traditional network problems,such as,transmission delay,packet loss.There are very few documents on attacks,but cybersecurity is an inevitable problem at present and has great research prospects.Second,most of the current triggering mechanisms are time-triggered.Time-triggered frequently sends unnecessary data,occupies communication channels,and affects communication efficiency.The event trigger mechanism first detects whether data needs to be transmitted,thereby greatly reducing channel occupancy.But how to combine event triggering mechanisms with attacks is more meaningful and challengingIn order to make up for the deficiencies,it is necessary to study and improve the existing filter design problems.In this paper,for the network attack problem,the corresponding attack signals are introduced respectively,and the corresponding processing filter design method is proposed.The main contents of this article are summarized as followsAiming at the attack of special circumstances,that is,the periodic attack problem,the H? filter design method of networked system is studied.Firstly,a periodic attack signal is given,and the filter input signal is redefined according to the characteristics of the attack signal.Then a novel event-triggered mechanism is given.Then,considering the influence of the network attack and event-triggered mechanism,the switching filter error system model is constructed.Using Lyapunov functional and free weighting matrix methods,the conditions for stability and performance stability based on this model are analyzed.Finally,the H? filter is designed by solving linear matrix inequalitiesThe event-triggered H? filter design method is studied for the attack in the general case,that is,the unknown periodic attack.First,give an unknown periodic attack signal and make a certain frequency or period limit;give a new event trigger mechanism to detect whether the sensor signal needs to be transmitted to reduce the communication burden of the filter design;then in the unknown period Under the influence of the attack signal,the event-triggered filter error system is established and is a switching system.By using the piecewise Lyapunov functional method,the conditions of system exponential stability and stable performance are obtained.Finally,the linear matrix inequality is used to solve the filter gain matrixFor a class of nonlinear networked systems,the design method of event-triggered H? filters under unknown periodic attack signals is studied.Firstly,an unknown period attack signal is given,and the filter input signal is adjusted under the influence of the attack.Then a new event-triggered mechanism is given to detect whether the sensor signal needs to be transmitted.At the same time,both the attack signal and the event-triggered mechanism are considered to establish the filter.The filter error system is a switching system.By using the piecewise Lyapunov functional method,linear matrix inequality technique and matrix convexity,the stability and performance conditions of the system based on T-S fuzzy model are derived.Finally,the filter is designed.