RoboCupSoccer is a soccer game played by robots, which commenced to promote the research and development of robot and AI technologies through friendly competition. While some other robots are radio- or remote-controlled, in this game, the robots have to think for themselves and autonomously make decisions to act.
RoboCupSoccer has eight leagues according to the robot size and form: Small Size, Middle Size, Humanoid (KidSize/TeenSize/AdultSize), Standard Platform, and Simulation (3D/2D).
The Robot Soccer leagues have established rules for each game, covering different field (pitch) sizes and numbers of robots. Some of these leagues of multiple autonomous robots playing soccer demonstrate strategic plays based on the mapping of the surrounding robots. The rules are amended at appropriate times due, for instance, to technological advance.
Small Size League
A Small Size League game is played between two teams of six robots each. The robots must be no larger than 18 cm in diameter and no higher than 15 cm. The playing field is a green carpet, 9 m long and 6 m wide. The game uses an orange golf ball. Information provided by a vision system incorporating four cameras installed above the field and judgments made by the referee are sent to the two competing teams. Using these sets of information, the robots communicate with one another via a wireless system so as to play the game autonomously and strategically.
Speedy movements and collaborative plays are the most attractive points of the Small Size League. This league is recommended for fans of human soccer games.
Middle Size League
Two teams of five autonomous robots each, within a 52 cm square in length and width and no higher than 80 cm, compete in soccer games. The playing field is a green carpet, a maximum of 12 m by 18 m. A Middle Size League game uses the same size 5 ball as is used in human soccer games, whose color is specified before the competition. Sensors, including cameras, and computers used for movements are mounted on each robot. The robots play the game strategically, sharing positional information with the other robots. Powerful movements are the most attractive feature of the Middle Size League.
The Humanoid League has three sub-leagues according to the robot size. Each sub-league employs robots walking on two legs. One challenge for them is to move and kick the ball accurately. Robots cannot move as nimbly as humans. However, their abilities to maintain balance while walking and kicking, and to recognize surrounding robots and the field, as well as the team strategies and other technical features, are improving year by year. The Humanoid League is expected to make a substantial contribution to the evolution of important technologies for the future development of humanoids.