Fixed-time Formation Control of AUVs Based on a Disturbance Observer

The paper is concerned with formation control of autonomous underwater vehicles (AUVs) subject to model parameter uncertainties and unknown ocean disturbances, a novel control scheme is developed, by which the formation can be achieved within a flxed time. The ocean disturbance is combined with the model parameter uncertainties as a compound disturbance. Then a disturbance observer (DO) is constructed to estimate the compound disturbance, which can be achieved within the settling time with zero estimation errors. Based on the DO, command fllter technique, flxed-time control and virtual trajectory, a formation control law is designed, by which the formation control can be achieved with all the states globally stabilized in a given flxed time. The efiectiveness of the proposed control scheme is demonstrated by numerical simulations. Copyright © 2019 Acta Automatica Sinica. All rights reserved.