Los Angeles Times
Monday, August 18, 1997

Playing for RoboKeeps

Technology: USC will send an unusual soccer team of five robots and their human creators to compete in the first Robot World Cup in Japan.
By JOE MOZINGO, Special to The Times

P rogrammed to recognize orange soccer balls, a USC team of robot athletes might prefer to attack a wall or a grad student's leg.
     But such are the problems to be worked out when putting together one of the first American robot soccer teams--to compete with four clubs next week in the first annual RoboCup (Robot World Cup) in Nagoya, Japan.
     Five players, built and programmed by a team of USC professors and students, will play soccer without human assistance.
      "Our robots are completely on their own," said student Rogelio Adobbati. "If they score, it's on their own merit. If they score on their own goal, it's their own fault. We try to blame them instead of blaming ourselves."
     Adobbati, a student clearly accustomed to having his legs attacked by Chihuahua-sized machines, nudges a defender named Marge away. His frustration mounts, though, when Marge and her teammates repeatedly slam head-first into walls or begin binges of spinning in circles.
     "It's like when you want a dog to fetch a stick and it just stares at you," Adobbati said.
     The robots are programmed to sense where the ball is and to chase it into the goal. They're supposed to cooperate with teammates to outmaneuver opposing players.
     Coaches will not tolerate ball hoggers.

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     "If one guy sees that the other team member already has the ball, he will not chase," said Wei-Min Shen, the computer science professor heading the project.
     The complexity of such a task is extraordinary. Just getting a robot to distinguish between a soccer ball and a human leg requires months of programming, Shen said.
     Sometimes their eyes detect the red hue in flesh and mistake it for the orange in a soccer ball.
     "Luckily, it's so small, it can't do any harm," Adobbati said.      To build the robots, the scientists took radio-controlled toy trucks and souped them up--essentially giving an eye and brain to each.
     The eye is an off-the-shelf digital camera that senses color and shape. With the brain--a laptop computer mounted to the player's back--it can gauge distance by the relative size of an object in its field of vision.
     The robots move on oversized spherical truck wheels that spin individually, allowing the robots to twirl with speed and agility. Shen estimated that each android costs about $900.
     The USC team--two attackers, two defenders and a goalkeeper, all named for characters on "The Simpsons" television series--will play four games at the corporate-sponsored tournament. Since the androids quickly drain power from their batteries, the games last only 10 minutes.

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     In Shen's league, the medium-sized division, the teams will come from universities in Australia, the United States and Japan. Shen and eight graduate students began working in their free time on the project several months ago. USC's Information Science Institute had decided to fund the team after its students placed second in an unrelated robot competition last year, Shen said.
     Beyond prestige, there is no reward in winning the RoboCup. But the tournament is connected to the International Conference on Artificial Intelligence and is considered a major event in this scientific field, Shen said. After the tournament, each team will share its experiences and its new technology with the others at a workshop.
     On USC's team, each player is programmed to perform a specific task on a 5-by-8-meter field. Maggie the goalkeeper, for example, has an eye on its side, so it is more capable of moving back and forth laterally to prevent goals.
     Experts say that combining the more abstract field of artificial intelligence with the real-world mechanics of robotics is a trying task.
     "One of the holy grails in artificial intelligence is to build a robot that can do the things that we do," said UCLA professor Richard Korf.
     Korf said that building and programming robots to do simple tasks that a child easily performs can be as hard as teaching them to be a chess master.
     "In some ways chess was easy," Korf said. "[That] world was very predictable. [But] if you play soccer, you know when you kick the ball it doesn't exactly do what you want."
     Soccer players also deal with the added element of time--they have to make decisions in split-seconds. And again, they have the problem of recognizing the ball, the goal, teammates and opponents.

* * *

     Shen, who has worked in the field of artificial intelligence for 14 years, is determined to overcome real-life obstacles. "It's more challenging," he said. "I always think that to really understand intelligence you have to try the real thing. You have to deal with sensing uncertainty or uncertainties in action."
     Shen hopes to someday build a robot that learns like a child, but can go where no human could--like the Los Angeles sewer system. A year ago, he proposed to the county Sanitation District a robot design called the "pipe fish," which would drift or swim down massive sewer lines to detect corrosion.
     Sewage always fills these trunk sewer lines, with no way to check for damage, said Dave Greenwood, a supervising engineer at the agency.
     Engineers thought the idea was clever, but county supervisors decided that the project would be too costly and postponed the proposal, Greenwood said. He added, "It's possible that we'd throw it in and never find it again."
     Now, Shen, like an overzealous father, devotes all his time to his soccer team. "I feel like they're my babies," he said. And when his babies get a little deranged and go for a human leg, he says he's nothing but proud. "No one else is doing it."

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