Control of -Autonomous Surface Vehicle Using Sliding Mode Control

Abstract

An autonomous surface vehicle (ASV) is a small autonomous boat that is expected to be used for automated investigations in radiation-contaminated areas or for unattended fishing, which will help the fishing industry, whose workforce is significantly decreasing. However, the discussion on the modeling and control of an ASV has mainly been based on those of a conventional ship. We have developed a micro-ASV (μ-ASV) on the basis of the concept that an ASV is a mobile robot. The translational motion of the μ-ASV is controlled by main thrusters, but its rotation is controlled by a bow thruster, not by a rudder as in an ordinary ship. Using the robot operating system (ROS), we demonstrated that the models of translational and rotational motions can be easily identified by adopting a distributed design using sliding mode control, in which the motion of the μ-ASV is controlled by main and bow thrusters. We also demonstrated that the translational and angular motions can be controlled by a simple dynamic positioning system (DPS). These findings allowed us to make the equations of motion and the control design of the μ-ASV simpler than those of an ordinary ship. A manual operation test using a joystick was conducted in the open sea. Promising results were achieved and are presented in this paper.