Robot dolphin can swim, hover, and walk like its natural counterparts
Designing an autonomous underwater vehicle (AUV) that glides seamlessly, maneuvers precisely, and can dynamically operate in different mediums poses a unique engineering challenge. It is no surprise, then, that developers of such technologies seek inspiration from marine life, perfectly evolved for that environment.
Lei et al. designed a robot model to mimic the ability of dolphins to hover and walk above the surface of the water. They applied fluid simulations to examine the required motion.
“During a visit to an aquarium, I observed dolphins not only swimming swiftly underwater, but also accelerating to leap out of the water and even maintaining parts of their bodies above the water surface for extended periods, achieving hovering and walking behaviors,” said researcher Dan Xia. “It led me to consider whether we could apply such dolphin behaviors to bionic underwater robots, enabling cross-medium movement and expanding their application scenarios.”
Dolphins achieve their motion at the water’s surface through coordinated movements between their bodies, caudal fins, and pectoral fins to generate vertical and horizontal forces. Mimicking this ability in an AUV could facilitate new applications.
The team analyzed the morphology of real dolphins to create their model and applied the observed fin motion to achieve the hovering behavior in a numerical simulation.
“Guided by the preliminary numerical simulation results, we will proceed with the design and fabrication of a prototype bionic dolphin robot,” said Xia. “This will include the design of the control system for the complex movements of the body, caudal fin, and pectoral fins. Then, we will conduct experiments in a real marine environment to validate the numerical simulation results.”
Source: “Hydrodynamics of standing-and-walking on the water surface by dolphins using collaborative movements of the body and fins,” by Ming Lei, Qingyuan Gai, Han Yan, Yuyao Li, Jinming Wu, and Dan Xia, Physics of Fluids (2024). The article can be accessed at https://doi.org/10.1063/5.0219768 .