Autonomous Docking for Maritime Autonomous Surface Ships Based on Dynamic Vector Field and Control Barrier Functions

This paper presents an autonomous docking guidance law for maritime autonomous surface ships (MASSs) to avoid different types of obstacles in complicated harbor environments. Firstly, a dynamic vector field-based guidance law is proposed to drive the MASS towards desired berthing position and direction synchronously. Then, the velocity optimization method is proposed based on the guidance velocity signal derived from the dynamic vector field. Through converting the obstacle avoidance constraints into velocity guidance vector constraints, the control barrier functions is utilized to construct a quadratic programming problem, which in turn leads to the optimal guidance velocity. By using the present method, the MASS can realize the autonomous docking task with automatic obstacle avoidance. Simulation results demonstrate the feasibility of the proposed method.