Security control scheme for cyber-physical system with a complex network in physical layer against false data injection attacks

In this paper, based on finite-frequency domain H∞ control techniques, security control issues are investigated for a cyber-physical system (CPS) suffering from false data injection (FDI) attacks on sensors and actuators, where the real system in the physical layer is a complex network system. First, for each subsystem of the complex network system, an H∞ proportion integral (PI) observer is designed to estimate the system states and attack signals on the sensors and actuators simultaneously. Second, a state feedback controller with attack compensation is proposed using the estimates of the attack signals and the states. Thus, an observer-based security control strategy against FDI attack is set up and the stability analysis is accomplished by frequency domain H∞ control techniques. Finally, a simulation example is given to illustrate the better performance of the proposed methods compared with the traditional H∞ method.