Research On Cyber-attacks Detection And Control Of CACC System

With the continuous development of Connected and automated vehicles,cooperative adaptive cruise control(CACC)has received widespread attention,which obtains the driving information of surrounding vehicles through the wireless communication network and adjusts the movement state of the vehicle in time,aiming to reduce energy consumption,improve traffic throughput and vehicle safety,and realize the intelligence of road traffic.However,there are still problems with the security of connected vehicles,the communication networks are vulnerable to cyberattacks.In order to improve security,the control system is designed must be able to detect and against such cyber-attacks.This paper proposed corresponding attack detection methods for the potential FDI and DoS attacks on the communication network of the CACC system.A reasonable reselient control strategy is designed under suffering from DoS attacks,and the effectiveness of the proposed detection methods and control strategy is verified through simulation and comparative experiments.(1)The analysis and studies the problem of FDI attacks on sensors in the CACC system and designs an attack detector based on random event-triggered frequency.Firstly,the CACC system is modeled,and tracking control of connected vehicles is achieved based on the MMSE estimator and model predictive control algorithm.Secondly,considering the network is vulnerable to FDI attacks,an attack detector based on random event-triggered frequency is designed according to the theory of binomial test,and the detectability conditions and theoretical proof of the frequency are provided.In addition,the applicability of the frequency detector is analyzed,and it is proven that the detector can not only detect common FDI attacks,but also detect stealthy FDI attacks.(2)The analysis and research on the detection of DoS attacks in the communication network of the CACC system.Firstly,the impact of DoS attacks on the transmission of data is analyzed and a platoon is modeled for the CACC system.Secondly,a high-gain observer is designed to detect DoS attacks and estimate the state of the vehicles as well as the transmission delay caused by DoS attacks.Then,the velocity observer is improved to ensure that the estimation error of the velocity converges to zero within a finite time,and the convergence of the observer is analyzed.Finally,a simulation system consisting of ten vehicles is designed in the FTP75 environment.Comparative experiments demonstrated that the designed observer reduced the relative estimation errors of the delay and confirmed the effectiveness and accuracy of the observer.(3)To mitigate the impact of DoS attacks on the CACC system,a time-delay compensation function is introduced based on the data transmission delay estimated values of the high-gain observer to design a new desired spacing.The control variable is adjusted according to the deviation between the actual distance and the desired distance to achieve observer-based resilient control,thereby achieving resilient control based on the high-gain observer.Simulation experiments demonstrate that the proposed resilent control strategy can reduce the impact of DoS attacks on the system,prevent collisions between vehicles,and improve the safety of the platoon.