Trajectory Tracking of Underactuated Marine Vessels with Inputs Saturations

This paper considers the trajectory tracking prob-lem for a class of underactuated marine vessels in the presence of inputs saturations. Indeed, this physical input saturation is a very common phenomenon in various practical applications, often causing a degradation in system performance and potentially leading to system instability. In addition to present a novel scheme for trajectory tracking of underactuated system, in this paper we apply a sort of auxiliary or augmented system concept to deal with this input saturations. This concept is not new in this paper, however, through detailed investigation of its design procedure, we find out that it is possible for us to (significantly) improve the tracking performance through proper design of the control parameters. Numerical study is also carried out to verify the effectiveness of the proposed tracking scheme.