Attack-Detection-Based Event-Triggered Transmission Scheme for Stabilizing Cyber-Physical Systems under Denial of Service Attacks

This article investigates an attack-detection-based event-triggered transmission scheme (AD-ETS) for cyber-physical systems (CPSs) subject to malicious denial of service (DoS) attacks. Due to the fact that DoS attacks can prevent transmissions without any specific rules, we characterize the effects caused by such attacks as arbitrarily bounded successive triggered-packet dropouts. On the one hand, a novel DoS attack detection strategy based on a transmission acknowledgement (ACK) scheme is developed to govern the switching of the event-triggered thresholds in real time. Compared with the existing resilient event-triggered transmission and switching-like event-triggered schemes, the proposed AD-ETS will make full use of historical ACK signals to distinguish DoS attacks from probabilistic packet dropouts and make a decision on switching event-triggered transmission strategy. Thus, both timely transmission and communication efficiency can be accomplished by using AD-ETS. On the other hand, the maximum allowable event-triggered parameter, which can guarantee the stability of the nonlinear CPSs, is derived by exploiting the input delay approach. Based on the derived maximum allowable event-triggered parameter, the relation between the secure event-triggered parameter and the number of successive DoS-incurred packet dropouts is pursued which supplies the basis of secure event design for event-triggered transmission under DoS attacks. Compared with the existing works, the secure event-triggered transmission strategy by considering successive DoS-incurred packet dropouts just depends on the event-triggered-threshold rather than nonlinear dynamics. At last, simulations on stabilization of vehicle longitudinal dynamics are conducted to verify the effectiveness of the proposed AD-ETS.