Simultaneous Stabilization and Trajectory-tracking Control of Underactuated Ships

Abstract

This chapter examines the problem of designing a single controller that achieves both stabilization and tracking simultaneously for underactuated surface ships without an independent sway actuator and with simplified dynamics. The proposed controller guarantees that stabilization and tracking errors converge to zero asymptotically from any initial values. In comparison with the preceding chapter, a path approaching the origin and a set-point can also be included in the reference trajectory, i.e., stabilization/regulation is also considered. The control development is based on some special coordinate transformations, Lyapunov’s direct method and the backstepping technique, and utilizes passive properties of ship dynamics and their interconnected structure.