Fall 1999 Table
Students Win International AUV Competition
by Andrea Cohen, MIT Sea Grant
in its pre-victory lap in test pond P-253. Photo: Corrina Chase,
Knaian and some 15 fellow MIT students spent much of last summer
sitting around his uncles swimming pool. But slackers theyre
not. Decked out with laptops and furiously writing code for Orca-2,
the small, autonomous underwater vehicle they developed, the students
were preparing for the Second International Autonomous Underwater
Vehicle (AUV) Competition. That preparation paid off, landing the
team first place for the second year running.
on what theyd learned from the original Orca, the MIT
students refined their vehicle for the 1999 competition, held in
Panama City, Florida, and sponsored by The Association for Unmanned
Vehicle Systems International and the Office of Naval Research.
"The big difference between this year and last year is that
we had learned the importance of design," says Knaian, who
received his M.S. in electrical engineering this past spring from
MIT and will receive his Masters in electrical engineering in 2000.
He adds: "Its a lot easier to change something on paper
than in reality."
make the 120-pound Orca-2 a robust, easily modified vehicle,
the students stacked two 24-inch long polyvinyl chloride (PVC) pipes
on top of each other, installed motors on both sides, propellers,
and hull modules that swing away on hinges for easy access for servicing
inner electronics. Vertical PVC pipes inside the hulls are fitted
with thrusters for diving and surfacing. The vehicle uses a magnetic
compass, a sonar altimeter, and a pressure sensor to sense its immediate
environment. The vehicle control system runs on a pentium-class
single-board computer. The control program can be accessed and modified
remotely via radio modem when the vehicle is near the surface, or
via an ethernet cable tether for deeper operation at close range.
designing and building an underwater vehicle is only part of the
International AUV competition, open to students at all universities.
The real test is navigating the vehicle along a submerged obstacle
course in a Florida test pond known as P-253. Operating autonomously
under computer control, vehicles must pass through a series of gates
submerged along the perimeter of the pond, then enter a specified
recovery zone, drop a marker, and surface, all within 20 minutes.
the 1998 competition, the MIT vehicle went through two gates before
beaching itself-an effort still strong enough to beat out the
other teams. This year Orca-2 successfully navigated through
all six gates to defeat teams from the University of Florida, Florida
Atlantic University, the U.S. Naval Academy and Stevens Institute
of Technology and bring home a $5,000 prize. Knaian notes that all
the teams had improved significantly and he expects both next years
course and competition will be fiercer.
Orca-2 cant compete with the likes of MIT Sea Grants
more powerful Odyssey vehicles right now, its designers show unlimited
promise. John Leonard, an assistant professor in MITs Department
of Ocean Engineering, was the students advisor on the project,
but states that his role was minimal. "Their achievement is
amazing, and they really did it all themselves," he says, emphasizing
the speed with which the students worked. And the project had no
shortage of MIT sponsors, including MIT Sea Grant, the Department
of Ocean Engineering, the Media Lab, the Department of Earth Atmospheric
and Planetary Sciences, the Center for Global Change Science, and
the Presidents Office.
the students are looking forward to taking Orca-2 to the
next level. "Were excited about next years vehicle,"
says Knaian. "We have the platform. People can write code for
it, do demos, and add capabilities." This years prize
money will help finance those efforts. And while the family pool
may be closed for the summer, MITs indoor chlorine drink is
available through the snowiest winter. For more information,