Human-in-the-loop COLREGs-compliant platoon formation control of maritime autonomous surface ships via finite state machine

This paper investigates the human-in-the-loop platoon formation control problem of maritime autonomous surface ships (MASSs) under the Convention on the International Regulations for Preventing Collisions at Sea (COLREGs). A human-in-the-loop virtual leader is introduced to incorporate supervisory human commands into the platoon navigation, such that human operators can indirectly regulate the sailing speed of the entire MASS platoon through speed inputs. To achieve path following and coordinated platoon formation, a cooperative path-following guidance law based on the line-of-sight method is developed for multiple MASSs along a parameterized path. To ensure safe navigation in compliance with COLREGs, a finite state machine is constructed to identify encounter situations, and safety constraints are formulated using control barrier functions. By solving a quadratic optimization problem, the optimal collision-avoidance surge velocity and yaw rate are obtained, enabling effective obstacle avoidance and collision prevention while preserving platoon navigation performance. Simulation results demonstrate the effectiveness of the proposed approach in achieving human-supervised platoon path following and COLREGs-compliant collision avoidance for MASSs.