As national soccer teams head into the second round of the World Cup this week in Germany, they're playing in the wake of RoboCup 2006, held last week in Bremen, Germany. Organized by the RoboCup Federation, these games, in which robots on wheels and legs compete in soccer "matches," are sponsored by a host of companies, including Microsoft. It might not get the fanfare of the World Cup, but this year RoboCup drew more than 400 teams from 36 countries.

Two Sony biped robots, Ami and Sango, prepare to act as commentators for a match at RoboCup 2006. (Courtesy of Colin McMillen.)

In 2006, though, a new twist was added to the event: robots not only played in the games, they also called the action.

The two new announcers are biped robots made by Sony and programmed by a team of computer scientists at Carnegie Mellon University, led by professor Manuela Veloso. Standing around two-and-a-half feet tall, the robots were originally built to showcase Sony's robotic technology; they can perceive in three dimensions, recognize faces and colors, and talk in multiple languages.

Veloso and coworkers gave two of these Sony robots, which they named Ami and Sango, a second career, by programming them to be RoboCup sportscasters. Veloso, a computer scientist with a special interest in robots that can observe, points out that the event's focus is artificial intelligence, not soccer, and that this "universally loved game" invites researchers to make robots that work in teams and respond to changing situations.

"Robot soccer is very dynamic and uncertain," Veloso says. As for the commentators, she says that humans still called and refereed the matches, and she "was curious about doing another task that was robot based."

The first challenge for Veloso's group was getting the robots to see a soccer game. They started with a ball. Each robot's "eyes," which are video cameras, can recognize colors, including an orange soccer ball. Veloso's students had already programmed many Sony robotic dogs to find and follow this orange ball while playing in the RoboCup. Now, over four months, they programmed the bipeds to track the ball with their eyes, with heads and bodies following, so that they face the action.

Meanwhile, the robots' onboard computers compare frames of video, recording changes in the ball's location and computing its speed, and sometimes announcing it ("The ball went 1.2 meters per second"). If the ball moves faster, they might comment "Nice kick." And if a player scores, the robo-announcers can recognize it, then search internal lists for phrases or actions to celebrate, such as waving their arms or saying "Awesome goal!"