Distributed path following control of multiple underactuated AUVs via constructing an interconnected system structure approach

This paper addresses the problem of distributed path following of multiple underatuated Autonomous Underwater Vehicles (AUVs). Stated briefly, the problem consists of steering a group of AUVs along specified paths while keeping a desired cooperative behavior. Strategy proposed is consisted of a path following control law and a coordination algorithm. Path following for each AUV is derived from Lyapunov and Backstepping techniques, which amounts to reducing an appropriately defined geometric error to a small neighborhood of the origin. Vehicle coordination is achieved by adjusting the speed of each vehicle to realize consensus tracking with the virtual leader AUV, under the constraints that the leader is only a neighbor of one or one subset of the following AUVs. Global stability and convergence conditions are derived under which the overall closed-loop system interconnected by the path following and coordination subsystem is Input-to-State Stable. Illustrative examples are presented and discussed to demonstrate the capability of the proposed method.