Research On Security Issues Of Dynamic Event-triggered Networked Control System Subject To Cyber-attacks

Over the years,network control systems have been widely used in various industries due to their high reliability,low maintenance costs,flexible configuration,and simple installation,such as drone flight,automotive industry,shipbuilding industry,automotive equipment,etc.The practical application of networked systems in many fields has demonstrated enormous value for scientific and technological progress and social development.However,the network system often faces the situation that the limited bandwidth is shared by multiple nodes.When the nodes in the system exchange data through the network,problems such as network delay,multi-packet transmission and time sequence disorder will occur,which will lead to the deviation of the transmitted data from the real value and the control failure.Therefore,the research on the network system must consider the problem of limited network resources.The introduction of the communication network also breaks the closure of the original control system,and the open network is very vulnerable to the influence of network attacks,and even causes the system to break down when it suffers serious attacks.This paper considers the network system security control and filter design based on the dynamic event triggering mechanism under the influence of network attacks.The main research contents of this paper are as follows:Firstly,the output feedback control problem of a class of event-triggered network systems subjected to multiple network attacks is studied.Two dynamic event trigger generators are installed at the sensor end and the observer end respectively to reduce the unnecessary data transmission frequency.Considering sensor-to-observer channel and observer-to-controller channel were attacked by spoofs and Denial-of-Service(Do S)attacks respectively,an output feedback controller was designed based on Dynamic Event-Triggering Scheme(DETS),and sufficient conditions for asymptotic mean square stability of closed-loop system performance were derived.Secondly,based on the improved DETS,this paper presents a security control method for cyber physical system against loss measurement and network attacks.In order to reduce the bandwidth occupation and the error effect caused by abrupt data,the DETS algorithm is proposed.Due to the unreliability of the network,sensor measurements may be lost randomly.In this paper,an observer-based controller is designed to protect the closed-loop system from loss of measurement output and network attacks while maintaining Asymptotic Stability(AS).Thirdly,this paper mainly studies the distributed filtering against outliers under DETS and network attacks on sensor networks.A novel distributed data release algorithm is proposed,which minimizes the data release rate and prevents burst data from being sent over the network.Considering the existence of outliers,saturation function is used to limit the polluted signal in the design of distributed filter to improve the filtering performance.At the same time,the damage of random Do S attack to sensor network measurement is considered.On the premise of ensuring the filtering error system AS,the sufficient conditions of the desired filter are derived to ensure the robustness of the filtering error system.