Resilient Observer-based Security Control for Cyber-Physical Systems under Multiple Attacks

The issue of security control for cyber-physical systems (CPSs) is now receiving a lot of attention. Among them, the network layer is more seriously affected by cyberattacks than the physical layer. In this paper, we investigate the denial-of-service (DoS) attacks and false data injection (FDI) attack on data transmission. Firstly, the FDI attack that exists in the actuator is estimated by proposing the observer. Then, due to the presence of DoS attacks in the sensor channels, the estimation effect of the former observer is affected. To solve this problem, a new resilient observer is proposed by introducing the switching mechanism. The proposed resilient observer can effectively reduce the adverse effects of DoS attacks on data transmission. Next, a false data estimation-based security controller is proposed, which can ensure the stability of the closed-loop system. Finally, a simulation is given to verify the effectiveness of the proposed method.