Robots Under Water, or Fun In the Sun (Mechanically Speaking)

Even robots are having more fun than I am this summer. Let's see, a week or so ago it was the RoboCup competition where robots played soccer. This past weekend, robots were cooling off in the pool at the 10th annual International Autonomous Underwater Vehicle competition.

Sponsored by the Association for Unmanned Vehicle Systems International (AUVSI) and the Office of Naval Research, the competition challenged students from 28 colleges and universities from around the world to design, build, and deploy autonomous underwater vehicles that could find pirate's hidden loot. To qualify for the competition, all of the underwater robotic entries had to be autonomous, able to sense their surroundings and respond accordingly, independent of any external control by an operator. All this for free admission to the pool and $20,000 in cash prizes.

Typical of the entries was the University of Southern California's SeaBee II -- a 50-pound underwater robotic submarine with three camera eyes, two arms, a water-cooling system, and related intelligence. Built by the USC Southern California Competition Robotics (USCR) team, SeaBee II is a BeoWulf Class I underwater cylindrical robot about 24-inches long and 7-inches in diameter. SeaBee II uses five thrusters for propulsion and depth control. They are arranged in two groups, with three thrusters aligned vertically and one pair aligned horizontally. The arrangement allows for five degrees of freedom to control the sub’s balance and orientation.

To recover the "treasure", the team had to design a simple arm mechanism, which sits underneath SeaBee II. When SeaBee’s vision system detects the X-shaped treasure and has centered itself above it, the sub is able to maneuver into position and lift it to the surface. According to Christian Siagian, a computer science doctoral student on the USCR team, the manipulator consists of two outstretched arms which are attached to the external frame of the vehicle "in a specific location so that the aft-most camera can judge when the sub has situated itself in the correct position to lift the treasure."

SeaBee’s many heat-producing elements, plus its Core Duo processors, created a heat problem, which the team had to solve before they could enter the competition.

So how did they do? Okay, but not good enough to win. That honor went to SubjuGator 6 from the University of Florida. The SubjuGator isn't new to the competition, having placed in the top spot 3 six times, including first place in 2005 and 2006.

The SubjuGator uses a single-board Intel Core 2 Duo based computer running the Windows XP provides processing power necessary for monitoring and controlling all systems. The behavior of SubjuGator is controlled with Microsoft Robotics Studio framework communicating with a network of intelligent sensors. The sensor systems include cameras, hydrophones, a Doppler Velocity Log, a digital compass, altimeter, and internal environment monitor sensors. The submarine also makes use of custom designed motor controllers with current feedback monitoring and other peripherals.

In the meantime, I was working all weekend.

Posted by Jon Erickson at 10:22 AM  Permalink