Students created a drone that swims underwater and flies

Four undergraduate students from the University of Aalborg in Denmark have developed a unique drone that can instantly switch from flight mode to underwater navigation and back again. The authors of the project — Andriy Kopachi, Mikolaj Dzwigalo, Pawel Kowalczyk, and Krzysztof Sierocki — created it as part of their graduation work.

In two semesters, the team fully designed, assembled, and tested a working prototype. The result is a robotic drone that can fly, dive, move underwater, and take off again without additional equipment.

The key technical feature was a system of adjustable pitch propellers. This is a design where the propeller blades can be rotated along their axis, changing the angle of attack. For flight, the propellers are set to a larger pitch, which provides lift, and for underwater movement — to a smaller pitch to reduce water resistance and increase efficiency.

In a YouTube demonstration video, the drone starts from the ground, flies a few meters, dives into the pool, swims underwater, and then calmly emerges and returns to flight mode. All this happens smoothly, without any noticeable delays or loss of control.

Structurally, the drone has a compact and ergonomic round body with a battery and control unit inside. Four double-blade screws are symmetrically mounted on sliding beams around the circumference. The form factor resembles an upgraded version of the 2015 experimental drone from the Rutgers University team. However, it used a scheme with four coaxial rotors and wired control, which significantly limited mobility. It is not yet known whether the Danish students were inspired by that project or went their own way.

It is interesting to compare this device with another engineering experiment that became known earlier this month. Back then, an enthusiastic developer printed a drone on a 3D printer that could walk on land, fly, and swim on the surface of the water. However, the model of students from the University of Aalborg has an important advantage — the ability to fully maneuver underwater and then take off without external assistance.

Meanwhile, Ukrainian marine drones are not yet able to fly, but this does not prevent them from effectively destroy Russian air targets.

Source: notebookcheck