Safety-Critical Guidance of Maritime Autonomous Surface Ship for Automatic Docking Based on Control Barrier Functions

This paper considers a guidance law design for automatic docking of maritime autonomous surface ship (MASS) moving in a complex sea environment containing static and dynamic obstacles. A safety-critical guidance scheme is proposed for MASS with a kinematic model. During the docking phase, the MASS operates with a fully-actuated mode and a safe guidance vector of surge speed, sway speed and yaw rate is developed with the aid of control barrier functions. The optimal guidance velocities for the docking phase are obtained by solving a quadratic programming problem such that collision-avoidance constraints will not violate. By using the proposed guidance method, the MASS is capable of reaching the its docking point with guaranteed safety. Simulations results are given to substantiate the efficacy of the proposed safety-certified control laws for automatic docking.