Timelapse image of the EagleRay transitioning from underwater to the air. Image: Matthew Bryant
Drones of the future will soon be able to submerge themselves underwater as well as take to the skies.
The idea of an aircraft being able to descend and submerge itself underwater has long been a dream of science fiction, and one reality had little hope of achieving.
Yet now, a team from North Carolina State University has shed more light on what it says is the first uncrewed, fixed-wing aircraft that is capable of doing just that – and it has the video to prove it.
Called the EagleRay XAV, the craft was developed with the purpose of finding a new way to track wildlife.
Rather than asking a drone to fly for hours on end, the EagleRay XAV would be able to splash down in the water to conserve energy.
Giving an example, the research team said the craft could track a fast-moving pod of dolphins while flying in the air, and then descend when the dolphins are taking a breather.
Once the pod starts moving again, the EagleRay can shoot up into the air and follow it once more.
“The EagleRay could also rapidly move underwater sensors from location to location. It could even perform underwater monitoring that most unmanned aerial vehicles can’t,” said William Stewart, who worked on the project.
“For example, sonar only works underwater. If you’re seeking a sonar target, the EagleRay could fly to a site, submerge to take sonar readings and then resume flight to take readings elsewhere. Historically, an aircraft would have to drop sonobuoys to collect sonar data.”
The project began in 2014 when the team won a research contract from Teledyne Scientific to develop the concept. By spring of 2016, it had developed a fully functional prototype.
Scalable concept
The current design has a wingspan of 150cm, a length of 140cm and weighs just under 6kg. Most importantly, the team said that the concept is completely scalable.
It has a dual-use propeller powered by an electric motor, which propels it through both air and water.
Warren Weisler, who also worked on the EagleRay project, said there are still some improvements left to be made to the design.
“We’re currently developing a custom controller for the EagleRay,” he said. “Existing controllers aren’t designed for a vehicle that transitions from air to sea and back again; they’re designed to be one or the other, with no transition stage.”
Details on the craft have been published in the journal IEEE Journal of Oceanic Engineering.
