Forget Cristiano Ronaldo, Wayne Rooney or Lionel Messi. With less than 100 days to the World Cup, it was four pint-sized robots that wowed crowds in Germany Tuesday with their footballing skills.

The four robots, about 60 centimetres (23 inches) high, named Rajesh, Penny, Sheldon and Leonard, part of the team that won the Robot Football World Cup in Austria 2009, played out an exhibition match at the world's biggest high-tech fair being held in Hanover.

The white robots use colour and line recognition to "see” the ball (orange), pitch (green) and goals (yellow and blue), explained Wiebke Sauerland from the B-Human team, part of the University of Bremen, which developed them.

By "seeing" the white lines on the pitch, the robots can tell where they are and adjust their movements towards the ball accordingly. When they sense they are near the ball, they kick out towards the goal.

"You programme them and then they do what they have been told to do. Normally," said Sauerland from the sidelines at the CeBIT fair, echoing many a football manager's agony.

The team from Bremen is due to compete in the 2010 World Cup for robots, held in Singapore on June 19, right in the middle of the "real" tournament in South Africa.

"We are confident, but there is a team from the United States that is really good," she said. The last competition drew 23 teams from around the world.