Synchronized path following control for multiple underactuated AUVs

This paper addresses the problem of synchronized path following of multiple under-actuated autonomous underwater vehicles (AUVs). The dedicated control laws are categorized into two envelopes, one is steering individual vehicle to trace along predefined paths, and the other is ensuring tracked paths of multiple vehicles to be synchronized, by means of decentralized speed adaption under the constraints of multi-vehicle communication topology. With these two tasks formulation, geometric paths following are built on Lyapunov theory and backstepping techniques, while injecting helmsman like behavior into classic individual path following control. Synchronization of path parameters are obtained by using a mixture of tools from linear algebra, graph theory and control theory. A simple but effective control design on direct inter-vehicle speed adaption with minimized communication variables, enables the multi-AUV system to be synchronized and stabilized into an invariant manifold, and all speeds converge to desired assignments as a byproduct. Rigorous proof warrants the synchronized path following control laws proposed.