Flexible Collision-free Platooning Method for Unmanned Surface Vehicle with Experimental Validations

This paper addresses the flexible formation problem for unmanned surface vehicles in the presence of obstacles. Building upon the leader-follower formation scheme, a hybrid line-of-sight based flexible platooning method is proposed for follower vehicle to keep tracking the leader ship. A fusion artificial potential field collision avoidance approach is tailored to generate optimal collision-free trajectories for the vehicle to track. To steer the vehicle towards and stay within the neighborhood of the generated collision-free trajectory, a nonlinear model predictive controller is designed. Experimental results are presented to validate the efficiency of proposed method, showing that the unmanned surface vehicle is able to track the leader ship without colliding with the surrounded static obstacles in the considered experiments.

I. Introduction

In recent years, unmanned surface vehicle (USV) has been applied in many fileds, e.g., search and rescue, water quality monitoring, platooning transportation, etc., to name a few [1]. Due to the limited transportation capacity of a single ship, multi-vessel formation transportation could be the future alternative solution. A fleet of USVs with platooning could be used for the transportation in few of riverside cities [2]–[4]. However, platooning of USVs suffers from the risk of collision. Considering this problem, the aim of this work is to develop an platooning method for follower USV to follow a leader ship in an open environment without colliding with other vessels and obstacles.