Security Time-Varying Formation Control for Multi-Agent Systems Under Denial-of-Service Attacks via Unknown Input Observer

The article investigates the security time-varying formation control problem when the communication network of multi-agent systems (MASs) suffers from Denial-of-Service (DoS) attacks based on switched controller, state observers and unknown input reconstruction (UIR). To begin with, for the follower agents with unknown inputs, through an interval observer, the estimations of unknown input (UI) and system state can be obtained asymptotically and simultaneously by a Luenberger-like state observer (LLSO) combining with a UIR. After this, a distributed control protocol (DCP) on formation tracking is proposed based on the UIR and the state estimation, which can compensate the UI successfully. Moreover, the time space is divided into three parts utilizing the transmission interruption caused by DoS attacks, and the gain of the controller is designed corresponding to three different DoS attack duration, respectively. With the help of some concept in switched system, it is demonstrated that the given formation pattern can be reached under the proposed DCP. Finally, to verify the effectiveness of the proposed methods, a vehicle cruise control system used as the simulation example is given.