Prepared for the dummy issue of Flipside, this feature examines the world of robot football and the prospects for a worldbeating mechanical team by 2050. The piece was updated for a later issue of the magazine that went on sale in late 2004.
Right now, they have more in common with R2D2 than Chelsea striker Adrian Mutu. But scientists around the world are working on robots that will be able to take on a top human football team, and win.
They have until 2050 to get their designs to run, kick and score like the professionals. And, if the programmers get it right, they won't dive, chop the legs out from under opponents, get drunk in bars and demand massive pay packets.
Bicycle kicks and diving headers will take a while for the robots to master. Not many of today's footballing robots have legs and those that do are only just learning to walk on a grass pitch. The teams that compete in the electronic version of the European Cup this month will be made up of cubes on wheels armed with flippers. But these boxes of chips are not the remote-controlled slaves of human operators.
Built-in controllers mean the robots can move by themselves. There is a long way to go as the robots have a nasty habit of running into each other rather than the ball. It is not because they are out to knobble the other team but because, right now, they don't know any better.
"Yellow cards are given regularly," said Bart Dirkx who builds football-playing robots for a research team at Philips Electronics in the Netherlands.
"You often see what I would call under-eights football. You see all these robots running all over the pitch after the ball," said Ken Young, who leads a team at the University of Warwick.
Botball teams are picking up better tactics and landing the ball in the back of the net. At Carnegie Mellon University in Pittsburgh in the US, Manuela Veloso has organised a team of robotic dogs that can learn which tactics will win. The Sony Aibo dog teams compete in a league of their own. The Aibos are not up to bicycle kicks and diving headers, but Veloso's team has succeeded in getting the robot dogs to pick up a dazzling variety of on-the-ball skills and work together to get round the back of the defence and knock the ball in.
Some of the robot dogs in the league have learned how to walk all by themselves. Scientist Peter Stone took Sony's robot dog Aibo and got rid of the old software that its creators gave it to let it walk on four legs. The robot was then given software that let learn how to walk again from scratch. Stone's Aibos now get around faster than the originals.
Soon, there will be two-legged robots with legs that are going to learn how to bend it like Beckham as scientists like Jacky Baltes at the University of Manitoba make them study how humans move. Like the motion-capture techniques used to bring Gollum to life in the Lord of the Rings, the robots will pick up how a human's legs move when walking, running and kicking by recording the output from sensors stuck onto them.
There is a long way to go before robots will run or kick as well as humans. The sensors and motors are not yet up to the job of letting the robot get across a grass pitch without falling over, only across the smooth surface of an indoor court. Baltes' work into how humans move has revealed new approaches. "Humans use vision a lot to balance. Try standing on one leg with your eyes closed and see how difficult it is," he said. By fitting the robots with cameras that concentrate on staying level, he reckons they will balance better too.
Robots could end up having advantages over humans in the game as they can add senses that humans cannot. They can send messages to each other much faster than any hand signals and take orders from a touchline coach.
In some games, robots get an overhead view of the pitch thanks to a mirror suspended over the pitch and cameras built into the tops of their heads and a computerised Alex Ferguson tells them how they should be playing.
Sensors such as laser scanners make it possible to locate the ball with millimetre accuracy, although they may not make it onto the pitch. "We would feel like cheating if we used those to play against humans," said Young.
Those incredibly accurate sensors could still be used on spin-offs from these footballing robots. The research is a game of two halves: the science that builds a metal and plastic Pele will go into robots that can save lives.
Laser scanners and radar will work where eyesight alone won't, helping to find victims buried under buildings after earthquakes or trapped by fire. The strength and mobility of a footballing robot will help it get to places human rescuers can't.
Other robots will turn up in the home. Dirkx expects his research at Philips to go into robots that can clean the house and, eventually, look after the elderly. And more scientists and engineers are getting into the area as the technology needed to build human-like robots gets cheaper. "There is a big explosion coming," said Baltes, and the football pitch will be the place to see it happen.