Output feedback secure control for cyber-physical systems against sparse sensor attacks

Abstract

Abstract This paper investigates the output feedback secure control problem for a class of cyber-physical-system (CPSs) under sparse sensor attacks. The considered CPSs are modeled as complex dynamical networks(CDN) with linear couplings. First, by defining a novel quadratic cost index, an optimal control policy consisting of a feedback control and a compensated feedforward control is obtained in the attack-free case. A necessary and sufficient condition for the optimal control policy minimizing the quadratic cost index is established. Then, a hybrid system that consisting all the potential attack modes is constructed and the corresponding optimal control policy for each attack mode is also obtained. Furthermore, an online switching method is proposed to pick up a proper control policy from the set of controllers. It is proved that the proposed online switching method guarantees the asymptotic stability of the system. Finally, a simulation example is given to verify the effectiveness of the proposed method.