Distributed Secure Observer-Based Adaptive Consensus Tracking Control for Uncertain Non-Linear Multi-Agent Systems Under Dos Attacks

In this paper, we investigate the adaptive secure consensus tracking control problem for a class of heterogeneous non-linear multi-agent systems with uncertain time-varying parameters against denial of service (DoS) attacks. Under DoS attacks, where the leader's dynamics and states are only known to a subset of the followers (subsystems), achieving leader-following consensus poses a significant challenge, as not all followers can obtain the reference signal in this case. To solve this issue, a novel distributed fixed-time estimator is designed to estimate the uncertainties involved in the leader's dynamics. By applying average dwell time theory and switching mechanism, a distributed resilient observer is designed to obtain the leader's states without any global information under the threat of attacks. Subsequently, an adaptive backstepping-based controller is designed to achieve consensus tracking for a class of high-order non-linear systems with time-varying uncertain parameters. It is demonstrated that, if the attack duration meets the specified limits, all estimation errors of the leader's dynamics converge to zero within a fixed time, and all observation and tracking errors remain globally uniformly bounded. Simulation results are provided to illustrate the effectiveness of the proposed control scheme.