Formation tracking and attitude synchronization control of underactuated ships along closed orbits

This article considers the problem of directing a family of underactuated ships to formation tracking a set of closed orbits and achieve attitude synchronization. It shows that our previous concentric compression design can be extended to deal with a general kind of non-convex, closed curves and the coordinated motion of underactuated ships. The condition of nonzero total linear speed of each ship is ensured by a potential function. Under the bidirectional communication topology, asymptotical stabilization is proved with the help of the invariance-like theorem and the extension of Barbalat's lemma. Theoretical results are proved by the numerical examples. Copyright (c) 2014 John Wiley & Sons, Ltd.