Adaptive event-triggered security control for networked control systems under hybrid attacks

This paper studies an adaptive event-triggered security control for networked control systems (NCSs) under aperiodic denial of service (DoS) attacks and false data injection (FDI) attacks. A state-FDI attack observer is designed to estimate the unmeasurable system state and unknown FDI attacks simultaneously. An adaptive event-triggered scheme (AETS) is proposed to conserve network resources while eliminating the impacts of DoS attacks, where the event-triggering (ET) parameter is adjusted according to the average value and the rate of change of neighboring state estimation errors. Based on the AETS, a security control strategy is designed to compensate for FDI attacks actively. Meanwhile, the entire closed-loop switched system is constructed under DoS and FDI hybrid attacks. Using the Lyapunov–Krasovskii function, the exponential stability conditions of NCSs with [Formula: see text] are obtained. Furthermore, the gain matrices of the observer, the ET parameter of the AETS, and the gain matrices of the active compensation controller are co-designed. Finally, the proposed scheme is verified by a numerical example and practical experiment on a brushless direct current motor NCS. The proposed scheme can not only defend hybrid DoS and FDI attacks in NCSs but also effectively relieve network congestion and improve communication efficiency.