Underwater surveillance, inspired by 007
NEW ORLEANS, LA. — An eel is undulating through coastal waters, powered by batteries and checking for mines. A jellyfish is actually a surveillance robot, powered by the atoms around it. Fins pick up intelligence while propelling a robot bluegill sunfish.
The U.S. Office of Naval Research is supporting baby steps toward making those visions of the future a reality. For instance, the jellyfish work is focused on how the creatures move in water, and how to mimic or even surpass their abilities. The robo-jellyfish is currently tethered to hydrogen and oxygen tanks, and ONR project manager Robert Brizzolara said he doesn’t plan to try making it move autonomously yet.
There’s plenty still to learn about basic hydrodynamics.
“We, as engineers, haven’t created anything that swims nearly as well as a very basic fish,” said Drexel University’s James Tangorra, who is working on a robotic bluegill. Partners at Harvard and the University of Georgia are studying the actual fish; he uses their findings to engineer imitations. “There are great things we can learn from fish ... the way they propel themselves; the way in which they sense water.”
Ultimately, the navy wants “the next generation of robotics that would operate in that very navyunique underwater domain,” said Jim Fallin, a spokesman for Space and Naval Warfare Systems Center Pacific, which is doing separate work in San Diego, Calif. One aspect is finding long-lived power sources to let drones loiter a long time to collect information, he said.
Possible uses include spying, mapping, and mine detection and removal.
The ONR studies are basic. The grants aren’t aimed as much at cre- ating drones as at understanding how things move forward underwater, Brizzolara said.
The navy uses torpedo-shaped drones and tethered vehicles to detect mines and map the ocean floor. But propellers and jets can be easily tracked on radar and sonar. Robots modelled after water creatures could be both more efficient and harder to detect, and could move through perilous waters without endangering people, researchers say.
Like the jellyfish work and the University of Virginia studies on manta rays, the eel research at the University of New Orleans is all about hydrodynamics. The spark is UNO professor emeritus William Vorus’s theory that sinuous undulations, though a slow way to swim, should allow forward movement without creating a wake.
Brandon M. Taravella, who studied under Vorus and is now an assistant professor of naval archi- tecture and marine engineering at UNO, sees the robot eel as a possible surveillance tool. But the ONR’s three-year, $900,000 grant is focused on making an eel and seeing whether it can swim without disturbing the water around it.
Other scientists have checked real eels, Taravella said. “It’s pretty high-efficient … but still has some wake.” Computer-generated models indicate just how a robot eel should move to get through the water without any drag. Creating one to do that is far from easy.