Resilient distributed secure consensus control for uncertain networked agent systems under hybrid DoS attacks

In this paper, the problem of resilient distributed secure consensus control for uncertain networked agent systems under hybrid denial-of-service (DoS) attacks is investigated. The current situation is that there exists a cyber layer connecting the network control units and a physical layer with specific physical links in the networked agent systems. Both the communication networks connecting the two layers and within the cyber layer may be attacked by DoS maliciously. These two attack scenarios have different impacts on the networked system. The former focuses on updating the control inputs timely, while the latter influences the connection weight of the cyber communication topology. Firstly, a distributed security consensus framework is proposed for the case that updates of signals are destroyed by DoS attacks between two layers, in which an acknowledgment (ACK)-based attack detection and a recovery mechanism are introduced, and a self-triggered based distributed control protocol is designed. On the premise of avoiding Zeno behavior, the relationship between trigger intervals and DoS attack characteristics is revealed. Secondly, corresponding asynchronous switching topology method is developed for secure consensus of the networked systems when DoS attacks are launched within the cyber layer. In addition, we found that large signals jump during switching and triggering will generate pulses and affect system stability. Therefore, a saturation function is introduced to constrain the fluctuation range of the signal. Finally, the effectiveness of the design scheme is verified by the simulation results of multi-robot systems.