Event-triggered secure observer-based control for cyber-physical systems under adversarial attacks

This paper investigates the problem of event-triggered secure observer-based control for continuous-time cyber-physical systems (CPSs) under actuator and sensor attacks. Under event-triggered scheme, the original plant is augmented into a discrete-time system, where the states and attacks are assembled into the state vector of the new system. Then, based on the augmented system, a discrete-time secure observer is presented to estimate the states and attacks. Besides, a novel secure observer-based controller, where the actuator attack estimations are utilized to neutralize the actuator attacks, is proposed. A cone complementarity linearization (CCL) algorithm is provided to co-design the desired observer and controller. It is shown that using the proposed secure observer-based controller, the states of the original plant converge to a small neighborhood of the origin despite attacks. Finally, an illustrative example is given to show the effectiveness of the proposed methods.