Path Parameters Consensus based Formation Control of multiple Autonomous Underwater Vehicles in the presence of ocean currents

This paper addresses the problem of steering a group of Autonomous Underwater Vehicles along specified paths while keeping a desired spatial formation in the presence of ocean currents. We show how Lyapunov and backstepping based path following control for a single vehicle and coordinated consensus tracking for multiple vehicles are brought together to yield a distributed control strategy, by which the problems existing in current designs that a common reference velocity signal being available to all cooperating vehicles are explicitly extended. The path following for each vehicle amounts to reducing an appropriately defined geometric error to zero asymptotically. The desired coordinated behavior is achieved by means of consensus on the velocity of path parameter of a virtual dynamic leader. The stability of the overall closed-loop system is analyzed mathematically. To demonstrate the controller proposed, simulations results are presented and discussed.