RoboCup: Meet the Beckhams of the future
- 04 June, 2003 12:08
Hundreds of soccer playing robots will grab world attention next month at RoboCup 2003 in Padua, Italy, and Australia is poised to conquer the world again.
Staged annually by the world's scientific community since 1997, a RoboCup match involves two teams of a few robots each playing soccer on a large table-turned-field, enclosed by panels to keep the ball in play.
Over 200 teams will represent more than 30 nations, including China, Chile, Iran, and Sweden. Last year's event in Japan attracted around 120,000 spectators and international television coverage, according to RoboCup organisers.
RoboCup's robots range from the two-legged ones that stand about 1m tall and play in the humanoid league, the computer-generated ones of the simulated environment, and the dog-like AIBO robots used in the four legged league.
It's the four legged league in which Australia has excelled. Last year's competition saw three Australian teams make the final four. Carnegie Mellon University of the US edged the University of New South Wales (UNSW) to win, but UNSW has won the league twice since it entered RoboCup in 1999.
Professor Mary-Anne Williams from the University of Technology, Sydney (UTS), said UTS robots, in the four-legged league, can pass and head the ball, and are capable of a range of kicks, including the bicycle kick made famous by such players as Brazil's Zico and Rivaldo.
Williams said the robots are capable of a range of kicks: including the one paw and two paw, and the one arm sweep. They can also bend over to head the ball. "To do the bicycle kick, the robot grabs the ball with its paws and throws it over its shoulder," she said.
According to Williams, a typical four-legged league match is 20 minutes of lots of kicking, less passing, and the occasional collision. There is no off-side, and robots that continue to collide are removed. Other rules include a three-second limit on holding the ball (excluding goalies), and only the goalie is allowed in the penalty box.
A robot in the four-legged league works via an in-built camera in order to 'see' colour. The field of play is surrounded by multi-coloured pylons (about 30cm high) which a robot's program uses to calculate its location and react accordingly. The colour of other robots and the ball are also used to calculate location.
"The robots work on a sense-think-act cycle," said Williams. "They use 25 frame-per-second cameras and infrared sensors to sense where they are. Then they think, which is the major processing operation, and once they've calculated their location this determines whether they kick or chase."
The AIBOs use a 192MHz CPU with 32MB of main memory.
"The cameras can pan while the robots are chasing so they know what to do when they get to the ball," said Williams.
Except for the humanoid league, the robot hardware in each RoboCup league is standardised. Four-legged league teams buy AIBO robots from Sony for about $3000 each.
"We don't touch the hardware. We write the modules for locomotion (how they run) and localisation (how they work out their relationship to other objects)."
The code, in C++, is usually written on PCs then inserted into the AIBO via a Memory Stick.
RoboCup AIBOs also communicate via a wireless network, said Williams. This lets robots share information about the location of the ball and how to get it.
"The robots can see about half the field. The challenges in programming are in assessment and what to do. How to kick the ball, where, etc," she said.
Robots are also programmed according to their position: the forwards will push up, for example, said Williams.
Along with Queensland's Griffith University, UTS will make its RoboCup debut in Italy. The faculty of IT at UTS last year gained funding of about $500,000 for three years of RoboCup participation. This has included building a lab "from scratch", said Williams.
Other Australian teams that have competed in RoboCup include the universities of Western Australia, Melbourne, Queensland, and Newcastle, and even the CSIRO.
Australian Open champions from January, UNSW have nine students rewriting their code "pretty much 24 hours a day", said Professor Claude Sammut.
"We've accumulated a lot of code through the years," he said.
The two-time world champions are working on improving teamwork for this year, he said.
"Lots of passing is far off yet. The first step in passing is getting the positioning right. You have to make sure the other robots know to support the carrier and not take the ball.
"In 2000, when we won [RoboCup's four-legged league], we had developed a new style of vision and walk, which put us ahead of the rest of the world. However, because the code is made open source at the end of every competition, the better teams soon caught up.
"Part of the reason we lost last year though was we didn't spend enough time on the penalty shoot-out code.
"Still, if you can get to the ball a bit faster than the others, that's the difference that's going to win you games," said Sammut.
The UNSW team leave for Italy on 31 June. The tournament allows teams a couple of days to tailor their robots' code to the colours of their new environment.
RoboCup's ultimate aim is to "by the year 2050, develop a team of fully autonomous humanoid robots that can win against the human world soccer champion team", according to its Web site.
It's achievable, said Williams.
"Most computer scientists and engineers think so," she said. "Science has been exponential in the last 50 years, and soccer doesn't need high cognitive skills. Intelligence today can be embedded into anything."
Whether the robots of the future will play as hot headed or vocal -- or even take their shirts off after scoring a goal, like some of today's players -- will remain to be seen.
In any case, young Beckhams and Kewells: beware.
RoboCup 2003 runs from July 5 to 11.