Airboat formation control and cooperative obstacle avoidance by integrating sliding mode control and dynamic window method in static obstacle environments

With the development of intelligent ships, conflicts may arise between formation maintenance and local obstacle avoidance in dense static obstacle environments. To address this problem, a Leader–Follower cooperative control method integrating sliding mode control and the dynamic window approach is proposed for multi-Airboat formations. First, a three-degree-of-freedom Airboat motion model and a formation-error system are established. A sliding-mode formation-tracking controller is then designed, and the closed-loop stability is demonstrated using Lyapunov theory. To address the lateral underactuation of Airboats, the lateral formation error is incorporated into the yaw-control channel, enabling indirect correction of the lateral position error. On this basis, a formation-oriented APF–DWA local planning method is developed. The candidate-trajectory evaluation of each Follower considers the formation-position error, inter-Airboat safety distance, obstacle clearance, and trajectory smoothness, while the relative priorities of obstacle avoidance and formation maintenance are adjusted according to the normalized local risk. Simulations are conducted for rhombic, triangular, swallowtail, and longitudinal formations in four randomly distributed static obstacle environments. The results show that the proposed method achieves collision-free arrival and recovers the prescribed formation after local obstacle avoidance, providing a coordinated trade-off among obstacle-avoidance safety, formation recovery, and path efficiency.