Comparing Nonlinear Adaptive Motion Controllers for Marine Surface Vessels

This paper deals with the design and evaluation of four controllers based on backstepping and different adaptive control schemes, which are applied to the motion control of a nonlinear 3 degrees-of-freedom model of a marine surface vessel. The goal is to make a comparative analysis of the controllers in order to find out which one has the best performance. The considered controllers are: Adaptive backstepping, adaptive backstepping with command governor, L 1 adaptive backstepping and L 1 adaptive backstepping with command governor. Numerical simulations are performed for target tracking along both straight-line and circular paths, with uncertain model parameters and an unknown disturbance. Motion control performance is evaluated by performance metrics such as IAE, ISE, ITAE and a novel metric named IAEW which combines control accuracy and energy use in one single metric.