Observer-based H_∞ control for cyber-physical systems encountering DoS jamming attacks: An attack-tolerant approach

In this paper, considering two typical attack strategies of a DoS jammer, a new kind of H_∞ control problem is studied for Cyber-Physical Systems (CPSs) with different transmission mechanism encountering DoS jamming attacks. By defining a concept of working subcycle, the concrete attack strategies of a DoS jammer can be generated by choosing different reasonable value combinations in a unified framework according to the DoS jammer's energy efficiency and stealthiness. Then, for two different transmission mechanisms, namely the time-triggered mechanism (TTM) and the event-triggered mechanism (ETM), in which CPSs can employ in its wireless channels, two DoS jammers employ different attack strategies and launch SINR-based DoS jamming attacks to decrease the quality of wireless communication. Considering the case that the CPSs do not know the DoS jammers' attack strategies, the corresponding H_∞ observer-based controllers are designed by using an attack-tolerant mechanism to achieve the desired H_∞ disturbance attenuation level, and the controller design problems are transformed to auxiliary convex optimization problems. Finally, numerical simulations are presented to demonstrate the effectiveness of the proposed H_∞ control methods and the varying of system performance under different interference power chosen by the DoS jammers.