Dynamic output feedback control for CPSs under transmission delays and sparse malicious attacks

In this paper, we study a class of discrete-time cyber-physical systems (CPSs) with transmission delays and sparse malicious attacks on both input and output transmission channels, and present design methods for secure observer and controller. First, the states and sparse malicious attacks of the original system are reorganized into the states of the new system obtained by an improved augmentation method (rather than a singular augmentation method). Then, based on the new system, the states and attacks can be reconstructed simultaneously by the designed Luenberger-like observer. Furthermore, a novel dynamic output feedback (DOF) controller is proposed using the estimated values of the attacks, and a cone complementarity linearization (CCL) algorithm is designed to obtain the controller gains. The results show that the closed-loop system is stable in the sense of Lyapunov that both the estimation errors and the original system states will converge to a small neighborhood of the origin. In addition, the correlation results without delay are given. Finally, two examples are given to illustrate the effectiveness and superiority of the proposed method.