Artificial intelligence lurks at the bottom of the pool. Designed by Cornell students, the unmanned sub Drekar – named after a long, sturdy Viking ship – probed the depths of a San Diego pool during the 14th International RoboSub Competition. The Cornell University Autonomous Underwater Vehicle team placed second during the competition, July 12-16, 2011. The Association for Unmanned Vehicles System International and the U.S. Office of Naval Research cosponsored the event in which thirty university, high school, and industry teams competed.
Drekar is more than motorized water toy. “The sub is artificial intelligence at its core, with sensors to measure velocity and cameras to view its surroundings,” said Tom Jackson, team leader for 2011-2012. Cornell’s team, made up of about forty undergraduates, designed the cooler-sized sub, including its brain-on-a-circuit-board software.
Software is the sub’s most important component. Clever programming, entirely student designed, allows the sub to sense and react to its surroundings, so that once it’s programmed, the team members can simply push a button and let the sub attack its course, with no one controlling it from the surface. “The software is a modular system, consisting of simple individual tasks, like determining its speed to its position, or to high level tasks, like ramming into a buoy,” explained Tom Brooks, the head of the software subteam. “We string them together to comprise our mission.”
During the RoboSub competition, vehicles are required to have cameras, as well as the ability to pick up an object, fire torpedoes, and drop markers along the obstacle course. They also must have a hydrophone system – a sort of artificial “ear” – that the students must construct themselves. The sub “hears” a chirping target in the pool, then moves toward it, all without input from any humans.
Cornell’s RoboSub win was the fruit of a year’s worth of work. Each year, the College of Engineering-based AUV team meets weekly during the school year to brainstorm and then craft the perfect sub. They start fresh with a new physical design each year despite an impressive record of wins at the competition in 2008 and 2009. (The team has been building onto its software for the past three years.) Jackson explained, “Our primary goal is to teach students how to build. If we use a previous year’s model, knowledge gets lost.” By the spring semester, once the vehicle is built, the team drops its sub into Teagle pool on Sundays to tweak its performance.
Cornell built subs like Drekar explore more than just the bottom of gym pools. The AUV team partners with the Cayuga Lake Floating Classroom Project, an organization that provides a traveling ship for educating about the lake’s ecology. Together, they use the unmanned subs’ cameras to learn about the plant life on the lake’s floor.
Other unmanned vehicles are heroes in settings not otherwise feasible for humans. Robot subs, for example, explored wreckage from an Air France flight that crashed off the coast in Brazil this April in waters too deep for manned subs. Engineers also hope subs can disarm mines or conduct pipeline inspections in the near future. Work by teams like Cornell’s continues to improve on unmanned vehicle technology, so that some day these autonomous subs can do other jobs that humans are safer not doing themselves.