Robust Formation Tracking of ASVs With Nonconservative Collision Avoidance: A Control Barrier Function-Based Approach

This article addresses the robust formation tracking control problem for multiple underactuated autonomous surface vehicles (ASVs) subject to bounded unknown disturbances. A high-order control barrier function (HOCBF) based collision avoidance formation tracking framework is proposed which combines a nominal controller and the HOCBF induced collision avoidance conditions. First, a predefined-time observer based nominal controller is proposed for the multi-ASV system which achieves formation tracking under general directed communication graphs. Then, a novel HOCBF based collision avoidance method is proposed for ASVs modeled by elliptical shapes to reduce conservatism introduced by conventional circular occupancy area assumptions. Finally, local quadratic optimization problems are established for the ASVs such that the robust collision avoidance formation tracking is achieved with minimal deviation from the nominal trajectories. Extensive simulation and physical experiments are conducted to verify the effectiveness of the proposed control strategy.