Stipulated-Time Formation Control of Networked Marine Surface Vehicles

This article presents a novel formation tracking scheme for networked marine surface vehicles facing external disturbances, based on a stipulated-time stability that stipulates the actual settling time. By using a class of regulation functions, a distributed observer is firstly developed to accurately estimate the leader's state exactly at a stipulated time, and then a stipulated-time sliding mode control protocol is proposed to achieve the formation tracking. Unlike the existing predefined-time formation control works that only specify the upper bound for the settling time and may cause over-engineering solutions, the proposed scheme exhibits the following features: 1) the actual settling time for the tracking errors is almost prescribed by a single parameter, regardless of the initial conditions and 2) the initial control input magnitude and system overshoot can be effectively reduced by skillfully choosing the regulation function parameters. Simulation examples are ultimately provided to showcase the effectiveness of the proposed control scheme.