RoboCup - soccer nuts or football crazy?

‘‘When I watch Ronaldo’s moves, our goal seems pretty hopeless,’’ Osaka University robotics professor Minoru Asada said. ‘‘But the spirit of RoboCup is one of challenge.’’

As the World Cup has arrived in Japan with all its feverish frenzy, RoboCup 2002 is expected to draw 193 robot teams from 30 countries to a stadium in Fukuoka city.

A rare pop-cultural outlet for science, RoboCup brings together the dreams of researchers from around the world to spread the word about robotics - a technology that’s crucial for less sporty uses such as disaster rescue, space exploration and nuclear plant clean-up.

The rules aren’t that different from human soccer. The robots scuttle along a carpeted pitch and shove a ball into a goal. An aggressive push may draw a yellow card. What’s missing: the offside rule and robot hooligans.

RoboCup began six years ago with a handful of teams with glitch-prone box-shaped robots on wheels that barely managed to move. This year, a dozen human-shaped robots are taking part for the first time. But don’t expect them to do much more than a penalty kick.

Besides the humanoids, RoboCup has four other leagues. Two leagues are for robots on wheels. In simulation league, programmers play virtual soccer. The four-legged league pits programming skills on the same machine, Aibo pet robots from Sony Corp.

To play soccer, robots must first figure out where they are, scanning the scene with digital cameras, calculate what they need to do and make the appropriate movements.

‘‘You have all the factors that are a real challenge to robotics,’’ says Bernhard Hengst, a doctoral student at the University of New South Wales in Australia, champion in the last two RoboCups in the Aibo league.

Along with the fun and games, the researchers see the gathering - previously held in Nagoya, Japan; Paris; Stockholm, Sweden; Melbourne, Australia; and Seattle, USA - as a serious opportunity for exchanging ideas.

‘‘It’s a great way to motivate the students,’’ Raffaello D’Andrea, engineering professor at Cornell University, one of the US contestants, said in a telephone interview from Ithaca, New York.

More than winning, D’Andrea hopes to display the fine techniques his team has developed to control robots more precisely.

Among the other ideas being bounced around are robots that can adjust their own programming to learn and grow.

Kazuo Yoshida, professor of system design engineering at Keio University, believes the future lies in building robots that understand good and evil, even possess a sense of purpose.

‘‘In the past, robots only needed to be able to do set things,’’ said Yoshida, who is bringing his students and wheeled robots to RoboCup. ‘‘More and more, people are looking for robots that are prepared for the unpredictable.’’

Scientists say humanoids make perfect sense because everything in the everyday world - stairways, doorknobs, kitchen knives and carpentry tools - are made in human sizes for human movement.

Peter Nordin, associate professor in complex systems at Chalmers University of Technology in Gothenburg, Sweden, says humanoids like those he is bringing to RoboCup will become household companions in a decade, probably at prices cheaper than a car.

Research shows people tend to be threatened by robots, and people, as it turns out, prefer short robots, Nordin said.

‘‘A good salesman is a little bit shorter. There’s a lot of psychology,’’ he said. ‘‘I’m not sure we will let a three-meter (10ft) high robot take care of our kids.’’

Today, the simplest act remains a tremendous task for a robot.

A robot at University of Tokyo that takes several hours to clear a table looks more like a crane at a construction site and can pick up only cups and cylindrical objects.

To walk, a robot must be programmed to bend its mechanical joints at certain angles down to fractions of a degree.

‘‘The human walk is smooth,’’ said Hiroyuki Ishii, a Waseda University student who is entering a wobbly humanoid called Ninja in RoboCup. ‘‘We don’t even think about it.’’

Hiroaki Kitano, one of the Japanese robot scientists behind RoboCup, believes robots will beat humanity’s best in soccer by a penalty kick because robots, unlike human players, will be programmed never to commit fouls.

‘‘Robots must be safe,’’ he said. ‘‘It’s easy to make robots that just stampede over people.’’