A planar path following controller for underactuated marine vehicles

Inspired by the previous work of Aicardi et al.[1] a path following controller for underactuated planar vehicles is designed by adopting a polar-like kinematic model of the system. The solution proposed does not generally guarantee null asymptotic path following error, but only its boundedness below an adjustable upper threshold. However, knowledge of the path curvature is not necessary, thus resulting in a much easier solution to implement when compared to the alternative ones available in the literature. Indeed controllers achieving perfect path following usually require not only the use of the path curvature, but also of its derivative with respect to the curvilinear abscissa. Furthermore, the proposed solution may be applied to the control of unicycle as well as underactuated marine vehicle models. Simulation results illustrate the performance of the algorithm proposed for path following.