Point-to-point navigation of underactuated ships

This paper considers point-to-point navigation of underactuated ships where only surge force and yaw moment are available. In general, a ship’s sway motion satisfies a passive-boundedness property which is expressed in terms of a Lyapunov function. Under this kind of consideration, a certain concise nonlinear scheme is proposed to guarantee the closed-loop system to be uniformly ultimately bounded (UUB). A numerical simulation study is also performed to illustrate the effectiveness of the proposed scheme.