Universal controllers for stabilization and tracking of underactuated ships

We examine the problem of universal control for underactuated surface ships with only surge force and yaw moment. Namely, a single controller is to be designed to achieve stabilization and tracking simultaneously. We propose, in this paper, the first universal controller of which the synthesis is based on Lyapunov's direct method and backstepping technique. Our result is extendible to the input-saturation when the surge and yaw velocities are considered as the controls. Numerical simulations are provided to validate the effectiveness of the proposed controller and to demonstrate its sensitivity with respect to model parameters. (C) 2002 Elsevier Science B.V. All rights reserved.