Transformable underwater docking mechanism based on origami-inspired deployable and bistable structures

The increasing deployment of autonomous systems, such as autonomous underwater vehicles (AUVs), highlights a critical need for robust and efficient recovery mechanisms. A significant challenge in extended autonomous operations is the limited onboard battery capacity, which necessitates reliable docking solutions. This paper presents a transformable underwater docking mechanism based on origami-inspired deployable and bistable structures, which can be mounted on a submarine. The proposed docking station system is divided into two components, which are the deployable funnel, and the landing station, respectively. The deployable funnel and landing station employe the Sarrus linkage and bistable structure, respectively. Additionally, the applied structures help reduce the burden on system control, enabling the use of a minimal number of actuators. The grasping forces of both components are analyzed, and the structural stability is simulated. The performance of the proposed mechanism is verified by conducting five underwater docking experiments in a circulation water tunnel with a free-stream velocity of 0.6 m/s.