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Competition at the tenth annual RoboCup robot football championships in Bremen came to an end over the weekend. Eleven of the 33 events were won by Germany. In second place was China with nine gold medals. Japan came third with six medals, while Iran came fourth with five.


No feel for the ball

Manfred Weise reports from RoboCup, the humanoid football world championships

The tenth RoboCup, the championship of football-playing robots taking place this year in Bremen, didn't start according to plan: rather than staying put and waiting for Jörg Kastendiek, Bremen's senator for industry and ports, to kick things off, the goalie – a machine – raced across the field, rammed into a table and spilled water over one of the computer scientists. That didn't stop those present from holding fast to their conviction. The statutes of the Robot World Cup Federation read: "By the year 2050, develop a team of fully autonomous humanoid robots that can win against the human world football champion team." Outside onlookers at the competitions taking place this week in Bremen might find that a daring prognosis.

The Humanoid League. Images courtesy of Messe Bremen and Robocup Federation

The robots of the Humanoid League, smaller than little-league players, wouldn't have the ghost of a chance against the oldest veterans. As the robots can't play matches, the RoboCup programme features competitions like penalty kicks and dribbling around obstacles. A robot can't just run onto the field and start kicking the ball around. Before it starts it's got to be properly adjusted: where am I? Where's the ball? Where's my opponent?

Players in the Humanoid League recognise the ball, the goals and their fellow players by their colours, so their image processing has to be finely attuned to the light. For this reason every RoboCup entry form gives an exact description of the lighting conditions in the hall, and the robots are not permitted to wear the same colour as the playing field, ball or goal. When spectators on the perimeter of the field wear ball-coloured T-shirts, it can happen that robots take them for the ball.

Sony Aibo dogs from the Four-legged League. Courtesy Messe Bremen

Martin Riedmiller, professor and member of the Neuroinformatics Group at the University of Osnabruck, finds it hardly imaginable "that robots will be able to beat human teams by 2050." But he has seen tremendous progress in recent years. As examples he points to the huge accuracy with which robots can pinpoint their locations in changing light conditions, their robustness and the precision of their attacking and defensive manoeuvres.

Still in its infancy, however, is team playing – which seems to require a higher degree of intelligence. That also goes for football intelligence (good players can anticipate how the game will develop), goal instinct (Gerd Müller: "If you start thinking in front of the goal, it's too late") and football emotions. But Riedmiller seems convinced that the problems of "intelligent behaviour" and anticipating game situations can be solved. "Already robots can behave reactively, without thinking, based on experiences," he says. "The goal is to have robots learn the correlation between certain actions and success or failure." Plus, there's still "a bit of time before 2050."

Humanoid players. Courtesy Robocup Federation

He sees more problems on the hardware side, with developing things like soft artificial muscles, quick-turning joints, robustness and energy supply. Robots need soft surfaces and artificial muscles to play against humans – instead of motors, gears and cables. And with the batteries and accumulators now available, robot footballers could play at most a couple of minutes – and not the regulation 90. For professor Rolf Pfeifer, head of the Artificial Intelligence Laboratory at Zurich University, solving the "motor-sensory question" in robot football has to take the forefront. Not the least, he says, because higher cognitive abilities and emotions are closely connected to bodily functions. But here research is still in its infancy. For Pfeifer there's little sense "interpreting cognitive aspects into the systems from above."

Humanoid line-up. Courtesy Robocup Federation

But the most difficult long-term task for constructors of humanoid footballers has to be heading the ball, as headers require an extremely complex combination of power and mobility, quick reactions, intuitive understanding of ball trajectories, experience and timing. And after all, one in five goals is a header. To sum up: in 45 years' time robots will be everywhere, but presumably the football stadium will be the last place where they still won't have a chance against humans.


The article was originally published in German in the Neue Zürcher Zeitung on June 16, 2006.

Manfred Weise works as freelance journalist for various IT newspapers, as well as the Neue Zürcher Zeitung. He is author of "Die Kurzmeldung. Theoretische Grundlagen und praktische Tipps" (The news flash: theoretical basics and practical tips), 2005.

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