Circular Formation Control for Networked Dynamic Autonomous Underwater Vehicles: Estimator-Based Approaches

This article investigates the circular formation control problem of networked dynamic autonomous underwater vehicles (AUVs) in a directed network. The objective is to make dynamic AUVs encircle a given target with specific a radius and velocity. The network topology among all AUVs is modeled by a directed graph containing a spanning tree, and the target is only known to one AUV. Estimator-based approaches with the backstepping technique are proposed for cases with or without communication. First, in communication-based networks, AUVs are allowed to transmit information via communication devices. A dynamic control law consisting of a distributed estimator is proposed. By analyzing with the perturbed system method, the multivehicle system achieves global exponential stability instead of asymptotic stability. Second, in communication-denied networks, AUVs depend only on the relative measurements from the onboard sensors. A dynamic control law consisting of a decentralized estimator is proposed. By small-gain analysis, the global asymptotic stability for the multivehicle system is established. To demonstrate effectiveness, simulation results are presented.