Safety-Critical Line-of-Sight Path Following Guidance of an Under-Actuated Maritime Autonomous Surface Ship Based on Robust Optimization

This paper is concerned with the path following guidance problem at kinematic level for a maritime autonomous surface ship (MASS) sailing in a constrained water with static and dynamic obstacles. A safety-critical line-of-sight (LOS) path following method is proposed based on control barrier functions. Specifically, an LOS guidance law is firstly designed to achieve the straight-line path following task. Next, collision avoidance with channel boundaries and static/dynamic obstacles are encoded in the control barrier functions, where robust optimization is used to ensure the constraint satisfaction in the presence of external disturbances. Then, safety-critical guidance signals are obtained by solving two quadratic programming problems. By using the proposed method, the MASS is capable of accomplishing the path following task with guaranteed input-to-state safety. Simulation results are given to substantiate the efficacy of the proposed path following guidance law for the MASS sailing in constrained water region subject to external disturbance.