Security control for cyber-physical systems under aperiodic denial-of-service attacks: A memory-event-triggered active approach

This paper is concerned with the security control problem for cyber-physical systems (CPSs) subjected to aperiodic denial-of-service (DoS) attacks. In order to mitigate the adverse impacts of DoS attacks, buffers are installed at both the event-generator and controller ends, allowing for the storage of pertinent historical information. A novel memory-event-triggered mechanism (METM) that incorporates dynamic parameter terms is introduced by taking into account previously transmitted state signals, with the aim of minimizing real-time data exchanges within CPS components. An active security control strategy is then formulated, leveraging the data from successful triggers to ensure timely updates of control signals, even in instances where the communication channel is compromised. The time-delayed closed-loop CPS, influenced by DoS attacks and network delays, is established using the interval decomposition method. A sufficient condition is derived, through the employment of an appropriate Lyapunov-Krasovskii functional, for achieving asymptotic stability along with an H-infinity performance index for the closed-loop system. The advantages and effectiveness of the theoretical results are showcased by two illustrative examples.