Observability Analysis of Networked Control Systems Under DoS Attacks

When networked control systems (NCSs) suffer from denial-of-service (DoS) attacks, system observability can be destroyed. To analyse this problem, this paper mainly investigates the observability of NCSs under DoS attacks. First, how DoS attacks destroy the observability of NCSs is revealed, where the original observability matrix needs to be reconstructed by considering the characteristics of DoS attacks. Second, the necessary and sufficient conditions for judging the observability of NCSs under arbitrary DoS attacks are proved, where the observability matrix needs to be calculated constantly. Third, the observability index and DoS attacks parameters are analysed, while the observability judging criteria under periodic and aperiodic DoS attacks are provided. Finally, the effectiveness and feasibility of the proposed method are verified by numerical examples.