Guidance law design for synchronized path following of underactuated unmanned surface vehicles based on distributed observer

This paper presents a guidance law design for synchronized path following of multiple underactuated unmanned surface vehicles (USVs) without using a global reference velocity. Firstly, a distributed observer is proposed to eliminate the need of reference velocity known to all the vehicles. Secondly, a line-of-sight based guidance law is derived to force each vehicle to follow a parameterized path. Finally, a neighbor-based coordination design is developed to synchronize the path variables. The equilibrium point of the close-loop system is shown to be globally uniformly asymptotically stable. Simulation results validate the efficacy of the proposed cooperative guidance law.