Duke Magazine-Racing Robots, Underwater-Student Snapshot-Jul/Aug 2002

August 1, 2002
Student Snapshot

Racing Robots, Underwater - Stephen Hsu, graduate student


Stephen Hsu, graduate student
photo:Les Todd

tephen Hsu's apartment has no beer signs or Tarantino movie posters on its walls. The walls are bare except for a rather detailed work schedule sheet, but the floors and tables are strewn with a colorful and tangled mess of circuits, wires, and microchips. At the center of it all is a flat board with extended corners and a cylinder attached in the center. Right now, she doesn't look like much more than an elaborate coffeemaker; but soon, she will strike fear into the CPUs of robots everywhere.

She is Gamera, an Autonomous Underwater Vehicle (AUV), capable of navigating through water and performing relatively complex tasks with no remote guidance. Hsu has been co-captain of this project with Chris Mailey '02 for about two years. They are heading the effort by the Duke Robotics Team, which provides a forum for the work begun in electrical engineering courses to continue on long-term projects like Gamera. Working from the initial design by electrical engineering professor Jason Janet (who teaches EE 141 and 142, "Linear Control Systems" and "Introduction to Robotics"), the team writes its own software, assembles the parts, and programs the robot's operations. The team has several participants assigned to specialized tasks, but Hsu works on the robot as if it were a full-time job--so much so that his living room resembles an IBM plant.

The goal of the project is coming up soon: the annual Autonomous Underwater Vehicle Competition, a four-year-old event sponsored by the Association for Unmanned Vehicle Systems International (AUVSI) and the Office of Naval Research (ONR). Each year's competition gives a different task for competing robots to perform. Last year, each AUV had to retrieve an object from the pool; this year, there are sunken barcodes spread throughout the water at different depths that must be located and decoded. Not as gruesome as Battlebots but just as exciting, to engineers.

Not surprisingly, the team from MIT has won the competition the last three out of its four years. "They're the ones we're chasing after," says Hsu. But if he's intimidated, he doesn't show it. Though the Duke team lost last year, "it took [MIT] four years to get them where they were, and in one year we had come a long way--we're really close to being on their level and developing a robot that can really challenge them."

Of course, it helps to have a trick up your sleeve--or in your wiring, as the case may be. Gamera is on the cutting edge, a first-of-its-kind AUV. Hsu says the big step toward a more perfect robot was to make it less robotic. "The question is, why would we try to develop all this new technology, when animals have evolved for billions of years and they've got it worked out?" he asks. Other AUVs' mobility depends on propellers, but Gamera does it just like a fish, or rather, a turtle, with good old-fashioned fins. New-fangled, too--Gamera is only the second robot to be equipped with this fin technology, called Nektors. Patented and trademarked by a local tech company, Necton Technologies, and developed in cooperation with Duke, the greenish, rubbery, plastic Nektors attach to each corner and paddle with much more maneuverability than a propeller. For propulsion technology, they're kind of cute.

A "fluid dynamic shell" is the final component to be added, realizing the AUV in the image of its namesake: Gamera, the massive, menacing sea turtle of the old Godzilla films. Even with the shell to decrease the drag coefficient, Gamera won't be the fastest bot in the pond. But Hsu insists that "the contest isn't really based on speed, but mission accomplishment." Equipped with the Nektor fins, Gamera's navigation will, they hope, be the most precise.

If Hsu's confidence proves justified, part of the competition's $10,000 award will be parceled out to the main workers, and the rest will be laid away for the team's future efforts. A first-place win would also bring renown to the Pratt School of Engineering. But Hsu '01, now a graduate student in biomedical engineering, says the prize is mainly "bragging rights." "And," he adds, "we make MIT look bad."

----Greg Bloom '03