Predefined-time time-varying formation control of networked autonomous surface vehicles: a velocity- and model-free approach.

This paper investigates the predefined-time time-varying formation tracking problem of the networked autonomous surface vehicles with the external disturbance and without model information. For addressing such a complicated issue, a novel model-free integrated algorithm without velocity measurement is newly designed, which consists of the distributed predefined-time estimator algorithm, the predefined-time extended state observer, and the predefined-time local sliding mode controller. Specifically, the distributed predefined-time estimator is designed based on the time-regulator function such that each vehicle can obtain the virtual leader's information indirectly. The predefined-time extended state observer is utilized to observe the external disturbance, the unmodelled dynamics, and the velocity states through a new parameter design method. Further, the local predefined-time sliding mode controller is constructed based on the above algorithms to address the considered control problem in a velocity- and model-free manner. Finally, numerical simulations have been performed to verify the main results. [ABSTRACT FROM AUTHOR]