UF's winning robotic submarine provides peek at the future

August 29, 2005

GAINESVILLE, Fla. — On the heels of the rescue of a Russian mini-submarine by a remotely operated sub, University of Florida students are leading their compatriots in the design of the next generation of robotic underwater vehicles.

The eight electrical and computer engineering students’ 30-pound submarine, SubjuGator, placed first in a national competition of 21 student-built robotic submarines earlier this month. Although still in the research stages, the sub points the way toward a future of smart, compact robotic submarines that could repair underwater pipelines, guard ports and conduct military offensive operations underwater.

“The military wants to have a significant percentage of its battle infrastructure done without humans in 10 years — by 2015, 30 percent of all U.S. military vehicles should be capable of autonomous navigation,” said Eric Schwartz, the electrical and computer engineering faculty adviser for the SubjuGator project. “These robotic subs could serve as spy-bots or plant explosives. You don’t always want to use humans because we value human lives and fighting is risky.”

On Aug. 7, the remote-controlled British “Scorpio” underwater vehicle disentangled a Russian mini-submarine that had been trapped for days beneath the Bering Sea, saving the seven-member crew. The rescue highlighted the capacity of remotely operated subs to lend assistance in situations that are either too dangerous or too deep for human divers – in this case, cutting the mini-sub free of fishing nets and other debris that had trapped it more than 600 feet below the surface.

The next step is to make submarines autonomous, or able to navigate and complete tasks without human assistance. UF teams have worked on that thorny challenge since at least 1998, when they first entered the then newly created Autonomous Underwater Vehicle Competition. But while the UF team placed in the top three in four of the previous competitions,
the Aug. 3-7 competition at the Space and Naval Warfare Systems Center near San Diego marked its first victory. The competition is sponsored by the Association for Unmanned Vehicle Systems International and the Office of Naval Research.

Three teams achieved one of the competition’s main objectives: Finding an underwater pinger, or sound-generating device, in a murky pond, and then rising to the surface directly above the pinger. But UF took first place because SubjuGator’s weight of 30 pounds was at least 40 pounds lighter than the other finalists.

“We forced ourselves into a small design by buying a small shell,” said Jim Greco, who earned his bachelor’s degree this spring and begins his doctoral program this fall, both in the UF department of electrical and computer engineering.

“All of our electronics had to fit within the shell. At UF, to save money, we make a lot of our electronics, whereas other teams might buy it off the shelf.”

Besides the electronics, the compact SubjuGator has five thrusters, which gives the computer controller complete three-dimensional control, said another team member, Jose Carlo Francis. It is powered by lithium polymer batteries that allow it to operate for 90 minutes. The design is completely new, although students used a few parts from previous years.

Greco, the team’s leader, said building the sub was a good introduction to collaboration and other skills of professional engineering.

“Our classes are great, but it’s mostly just theory,” he said. “There aren’t a whole lot of practical applications, and this allows you to get a leg up.”

He added that one problem with today’s remotely operated submarines is that they require a cable or other communications link to the operator at the surface.

“If you’re going down into the Marianna Trench, the deepest spot on Earth, you can’t exactly drop a cable in there,” he said.

Robotic subs, by contrast, remove this impediment, but as Greco noted “they have their own problems to work around.” One major challenge: programming the subs to “see” and react to objects or changes in the terrain, a difficult task for land-based robots made even harder underwater by limited visibility and difficulty of controlling the vessel.