Research On Network Control System Security Strategy Under Network Attacks

Network control system is a closed-loop feedback control system formed by the system components connected through a shared communication network.In recent years,the continuous development of network technology has brought many conveniences to the control system,and it has also brought security problems to the system.The security of network control systems has attracted widespread attention from researchers and government agencies at home and abroad.Denial of Service attack is one of the common,effective and easy-to-implement methods of attack in network control systems.It disrupts system communication by interfering with or exhausting system resources.For closed-loop networked systems with high real-time requirements,DoS attack will cause system control performance degradation and even system instability.Therefore,this paper will focus on DoS attacks at different time scales,from the perspective of networked control systems,security analysis and security defense strategy design,the main work is as follows:(1)Design of DoS attack defense strategy based on predictive control method.Firstly,considering the nonlinear networked system with unknown system parameters,the model-free adaptive control method is adopted to design the data-driven predictive control method to compensate the data loss caused by the DoS attack,and the event trigger mechanism is introduced to reduce the burden of network transmission.Secondly,considering the networked linear control system,the model-based predictive control method is used to design the adaptive predictive compensation algorithm,which is based on the historical strength of the DoS attack to predict the compensation interval to prevent future DoS attacks,so as to reduce the conservative of prediction compensation.Finally,the effectiveness of the designed defense strategy is verified by an example simulation experiment.(2)Resilient performance analysis and trigger control parameters design of predictive control system under DoS attack.The virtual trigger mechanism is introduced to construct a system defense architecture based on predictive control.The switching system theory and the average dwell time analysis method are used to analyze the resilient performance of the predictive defense system under DoS attack.Obtain the DoS attack constraints that guarantee the stability of the system.At the same time,the joint design method of trigger parameters and control parameters based on linear matrix inequality LMIs is given,and the validity of the theory is verified by simulation.(3)Design of DoS attack defense strategy based on redundancy thought.For the large time scale DoS attack,a dual event trigger communication mechanism based on redundant transmission channels is constructed.Furthermore,the stability of the designed system is analyzed based on Lyapunov stability theory,and the parameters design method of the dual-trigger control structure is given.Finally,the effectiveness of the designed defense strategy is verified by numerical simulation.The innovation of this paper lies in the DoS attack against different time scales,using predictive compensation methods and redundancy ideas,and system security analysis and security control strategy design to achieve the safe and stable operation of the networked system.