Hybrid underwater glider for underwater docking: modeling and performance evaluation

The development of a novel type of hybrid underwater glider that combines the advantages of buoyancy-driven gliders and propeller-driven autonomous underwater vehicles has recently received considerable interest. However, few studies have considered a hybrid glider with docking capability, which would expand the glider's applications. This study presents a hybrid glider with a rotatable thruster for realizing underwater docking. A tailored dynamic model of the hybrid glider is derived, and the motion performance is evaluated by simulations and experimental tests. A comparison between the experiments and simulations shows that results are in agreement, thus indicating the feasibility of the dynamic model and the accuracy of the hydrodynamic coefficients. In addition, the hybrid glider open-loop docking tests validate the feasibility of the mechanical docking system. Moreover, the experimental tests also validate the glider's different functions and indicate that the hybrid glider with rotatable thruster has high maneuverability even at low speeds. Thus, this type of hybrid glider can be used for underwater docking.