Computer Science Research Focuses on Robotics

By Robin Herron

The movie A.I. notwithstanding, don't expect to see human-like robots in your neighborhood anytime soon. "We're a very long way from that--two hundred years or maybe more," says Sean Luke, associate professor of computer science.

But building a robot like David in A.I. isn't Luke's goal. He and other professors in George Mason's Computer Science Department are investigating various facets of robotics that may have more immediate applications.

"Up until three or four years ago it was prohibitively expensive for us to get involved in robotics. Now we have robots that are robust and adaptive--and affordable," says Kenneth De Jong, professor of computer science.

Computer Science faculty now use off-the-shelf robots designed for research, which range from small $200-$300 robots built from Lego kits to large barrel-size robots that cost almost as much as a Volkswagen Beetle. Most of the research, however, is done by simulation, with an actual robot used only for final testing, De Jong says.

Luke, whose interest is in evolutionary computation, has used only his computer for some robotics research. Using the model of a soccer game for his study, he created white dots--softbots--on his computer screen. These softbots became the soccer teams. The computer developed programs and then played the teams against each other, selecting the better ones and "breeding" them, thus creating new generations of improved programs. In the early rounds, the softbots all went to the ball. Eventually, they "learned" that if one or two stayed back, the ball would eventually pop out of the pack and they could block it from going into the goal. Finally, the computer teams learned that their chances to score increased when "players" spread out into strategic positions.

The learning process that Luke demonstrated showed that robots could be programmed to work in teams with other robots. The process' practical applications might be used in a battle simulator or search and rescue efforts. Another application might be in building space stations, where sending each command to a robot from earth is tedious and time-consuming. "You need to have the robots be partially autonomous so they can coordinate with humans and other robots," says Luke.

Could a robot be programmed to assist an elderly person in a home setting? To do that, it would need a kind of computer vision that would let it map out three-dimensional objects so it could navigate the home. Using the department's largest robot, dubbed "Elvis," Jana Kosecka, associate professor of computer science, is developing algorithms to help the robot build a geometry of its world.

Elvis is equipped with ultrasound sensors to "see" objects at long distances, infrared sensors to sense objects up to a few feet away, and a video camera to record what it's "seeing." Elvis's short-term goal is to tour the Computer Science Department without bumping into things. The long-term goal is for Elvis to interact with objects. "We want to push the complexity of the kind of environment they're in as well as the kind of interactions," Kosecka says.

Zoran Duric, assistant professor of computer science, works on tracking human movement. Used with a video camera, his computer programs recognize human behavior and human gestures using color and objects' edges or boundaries, differentiating the human subject from its background and tracking his or her movement. The programs can also determine whether the subject picks something up or drops something.

Although it may sound simple, tracking movement is actually quite complex, Duric explains, and he compares it to developing notation for music or choreography for ballet. Duric's programs could be used by a robot outfitted with a camera for surveillance or safety purposes, such as monitoring children near a busy intersection. The research could also be used in video games and animation, in searching video to find specific events, or in sports analysis, for example, to help a golfer analyze his or her swing.

Enthusiastic about the possibilities of robotics, De Jong relates a list of practical applications. "Robots have a long association with industry and the military," he says. "Robotic vehicles can be used in dangerous or unpleasant situations, like a nuclear waste site or the sewer system in New York City. A robot could help long-distance truckers navigate or provide an alert mechanism because a robot doesn't get sleepy or distracted.

"Almost every object has a computer chip and can be programmed to be more intelligent or autonomous," De Jong says.