Prescribed-Time Consensus Tracking of Multiagent Systems Under Denial-of-Service Attacks With Application to Unmanned Vehicles

This work addresses the prescribed-time consensus tracking problem for multiagent systems (MASs) under denial-of-service (DoS) attacks, where certain communication links between agents are intermittently disrupted or rendered unavailable. Due to the DoS attack, although appropriate defense mechanisms may be employed to recover some of the attacked or backup connections, the communication topology evolves from a fixed graph to a time-varying switching topology. This ever-changing network introduces significant challenges, leading to discontinuities in the Laplacian matrix, which complicates both prescribed-time controller design and stability analysis. To tackle these challenges, a prescribed-time stability lemma (Lemma 5) is developed along with a vital inequality (Lemma 6) that establishes the quantitative relationship between Lyapunov functions across switching instants. Building on these results, a novel distributed observer is designed to accurately estimate the state of the leader within the prescribed time, despite the occurrence of DoS attacks. Subsequently, a coordinate transformation and a fractional-power backstepping technique are introduced to construct a control protocol that achieves prescribed-time consensus tracking. The proposed approach is rigorously supported by theoretical analysis and is further validated through its application to multiple unmanned vehicles.