Cross-track formation control of underactuated surface vessels

The problem of cross-track formation control for underactuated 3-degrees-of-freedom (3-DOF) surface vessels is considered. The proposed decentralized controllers make the vessels asymptotically constitute a desired formation that follows a given straight-line path with a given forward speed profile. The proposed controllers consist of two blocks. The first block, which is based on a Line of Sight (LOS) guidance law, makes every vessel asymptotically follow straight line paths corresponding to the desired formation motion. The second block manipulates the forward speed of every vessel in such a way that they asymptotically converge to the desired formation and move with a desired forward speed profile. The results are illustrated with simulations.