Collision Avoidance for Autonomous Sailboats Based on RRS Protocol

Abstract

Autonomous sailboat as an energy saving robotic vessel driven by wind, is becoming an emerging trend in ocean sampling, surveillance and management. Hereby, collision avoidance for autonomous sailboats appears to be an insurmountable problem due to its restricted manoeuvrability. In this study, we propose a method to realize the collision avoidance for autonomous sailboats under the Racing Rule of Sailing (RRS). Using the safety circles concept, the speed and heading information of the autonomous sailboats are used to predict and determine the collision risk. Then the correct RRS rule is matched according to the collision situation when the Closest Point of Approach (CPA) of autonomous sailboats is less than zero. And collision avoidance response is planned and implemented accordingly. The proposed method was implemented and verified in experiments. Four different sailing cases were discussed and demonstrated with successful collision avoidance for autonomous sailboats.