1. Archive

Robot subs to add depth to ocean search efforts

Onboard computers and sensors will guide the craft, improving on older devices that must be tethered to ships.

Underwater ROVs _ remotely operated vehicles _ that found John F. Kennedy Jr.'s plane and wreckage from the TWA and Swissair crashes might be replaced by robot submarines in the not-too-distant future.

Navy and civilian researchers are developing small, low-cost Autonomous Underwater Vehicles, or AUVs, that could be deployed in greater numbers to search larger areas of ocean bottom and do it faster than ROVs. They also could be used to hunt for mines, map oceans and other tasks.

ROVs must be tethered to a ship to receive power and human control. The new robosubs will operate with their own battery power and get their guidance from onboard computers and sensing devices.

"Once it leaves the dock, there's no more interaction," said Daryl Davidson, executive director of the Association for Unmanned Vehicle Systems International, a trade group based in Washington, D.C.

"If you want to use the JFK scenario, instead of having a couple ships that are towing ROVs or towing sonars, you could have one ship that could dump numerous autonomous underwater systems, and they could each kind of track their own preprogrammed missions," Davidson said.

Aircraft even could drop the small subs by parachute, said Tom Curtin, program manager for the Office of Naval Research in Arlington, Va.

"You could get them out there very quickly. You don't have to wait for a ship coming from Florida three days away," Curtin said. "They'll work in all weather. They'll work at night."

The Navy is primarily interested in AUVs to hunt for sea mines and obstacles. The autonomous subs could work while sailors and Marines stay out of harm's way.

A mine-hunting AUV is expected to join the fleet in three to five years, said Barry Dillon, chief of science and technology for Navy's Coastal Systems Station near Panama City Beach.

It would ride near the surface with an antenna sticking out of the water to transmit real-time data from synthetic aperture sonar and electro-optics that would plumb the depths with sound waves and laser light. These sensors also are a significant advancement and got their first real-world test in the Swissair search in 1998 aboard a platform towed behind a ship.

"It was such a violent accident they needed something with better resolution that can go deeper," Dillon said.

The first operational AUV would find mines so they could be neutralized by existing weapons, but the Navy also is working on a version that could do that job itself.

"Obviously, if you are going to neutralize, you might lose the vehicle, so you want to be able to build it cheap enough that you can afford to do that," Dillon said.

Other potential tasks include finding shipwrecks, surveillance, intelligence collection and harbor security as well as ocean mapping and exploration.

"We spend a lot of time going to outer space," Dillon said. "But the ocean is probably less understood. These type of systems are going to open up that world for us."

AUV technology, however, is in its infancy.

To generate new ideas and create a talent pool of potential researchers, the Navy and Davidson's association sponsored the second annual International Autonomous Underwater Vehicle Competition on Aug. 8 at the Coastal Systems Station.

Five teams of college students participated, and Massachusetts Institute of Technology repeated as champion with its sleek, black Orca. The University of Florida's boxy orange and blue SubjuGator was second, followed by entries from Florida Atlantic University, the U.S. Naval Academy and Stevens Institute of Technology of Hoboken, N.J.

The excitement of hands-on learning matched the thrill of victory for MIT graduate student Ara Knaian, of Newton, Mass.

"You can go ahead and build all the circuits and boxes you want, and that can be very exciting if you are of a certain persuasion," said the electrical engineering major. "But it's a lot of fun to go and build things that actually cause motion to happen."

Perhaps the most innovative design was Florida Atlantic's SQUID, short for Submersible Quiet Underwater Intelligent Driver. It looks like a small artillery shell and weighs a little more than 20 pounds, about a 10th as much other entries.

SQUID has no propeller, fins or rudders, using a vectored thruster to steer as well as propel the tiny sub. Similar devices are being used to give fighter planes greater maneuverability by changing the direction of their engine exhaust nozzles.

What really sets AUVs apart, however, is the computer software that makes them true robots, freeing them from the constraints of remote control.

"Once you break that tether," said Navy researcher Curtin, "it's not just a little step."