Global tracking for an underactuated ships with bounded feedback controllers

TL;DR

This paper introduces a globally stable, bounded-input feedback controller for underactuated ships that ensures effective tracking without velocity measurements, demonstrated through simulations on a marine vessel model.

Contribution

The paper develops a novel global tracking controller with bounded inputs for underactuated ships, applicable with or without velocity measurements, using a benchmark vessel model.

Findings

Controller achieves global asymptotic stability.

Bounded control inputs are maintained.

Simulation confirms effectiveness in marine vessel tracking.

Abstract

In this paper, we present a global state feedback tracking controller for underactuated surface marine vessels. This controller is based on saturated control inputs and, under an assumption on the reference trajectory, the closed-loop system is globally asymptotically stable (GAS). It has been designed using a 3 Degree of Freedom benchmark vessel model used in marine engineering. The main feature of our controller is the boundedness of the control inputs, which is an essential consideration in real life. In absence of velocity measurements, the controller works and remains stable with observers and can be used as an output feedback controller. Simulation results demonstrate the effectiveness of this method.