RoboSumo Rules

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About Robot Sumo

Sumo is a very popular sport in Japan and is known around the world. Two really big guys get up on an elevated platform, the Sumo ring. The goal is to push the other guy out of the ring or throw him to the floor. It's basically king of the hill. The national Sumo competition is held in Japan the middle of each odd numbered month (January, March, etc.).

Robot Sumo started in Japan and is now the most popular robot competition worldwide. We use the simplified rules below, which are based on the official Japanese rules.

Divisions

There will be two divisions in our competition: a Junior Division for grades 5 - 9, and a Senior Division for grades 9 -12.

Objective

Push the other robot out of the Sumo ring.

Specifications

Sumo Ring

The Sumo ring is made of black painted plywood. There is a 5 cm wide white painted border. Two thin starting lines mark the no-mans zone in the middle. Robots must start behind these lines.

Robot Construction

The robots must be totally autonomous (brains on board) meaning, no remote control or human intervention of any kind, and no tethered, IR, or RF connection to a host computer.

Junior Division (grades 5 - 9)

• Parts are limited to any official or compatible Lego Mindstorms or Mindstorms NXT piece, rubber bands, removable tape, and cardboard. Not allowed: glue, anything that damages the Lego parts, vacuum or sticky wheels.

• A maximum of 3 motors may be used.

Senior Division (grades 9 - 12)

• Any type of robot construction is allowed, including kits and custom-built robots. The VEX robot kit is a popular choice.

• Not allowed: vacuum or sticky wheels.

Match Rules

• A match consists of up to three games.

• The first robot to win two games wins the match.

Game Rules

• At the start of each game, a die will be rolled that determines which way to orient the robots: face to face, side to side, or back to back. The players will then place their robots in the indicated positions.

• When given the signal, both players press their start buttons simultaneously then move back out of the way so spectators can see.

• Players cannot touch their robots or enter the ring for the remainder of the game.

• The robot must start moving 5 seconds after the start button is pushed. If a robot does not wait 5 seconds it is disqualified.

• A robot wins a game when it pushes its opponent out of the ring or if the opponent moves out of the ring by itself. A robot is out of the ring when any part of it touches the floor, even if that part is no longer connected to the main body of the robot.

• If any of the following occur the game will be restarted:
  1. Both robots are locked together and stop movements for 30 seconds, or are stuck in the a repetitive pattern for 30 seconds. 
  2. Both robots move or stop for 30 seconds without touching each other.
  3. Both robots at the same moment touch the space outside the Ring.
     

• If one robot stops it's movement for 30 seconds, he shall be considered not having the will to fight, and the opponent shall win the game.

• If neither robot moves outside the ring within 2 minutes, the judge will decide the winner based on technical merit of the movements and operation of the robots and attitude of the players during the game.

• Your robot may not send messages that interfere with the operation of the other robot.

• Your robot cannot be designed to deliberately damage the other robot or the Sumo ring.

Deciding the Winner in Each Division

If 20 or fewer teams compete in a division, the 1st, 2nd, and 3rd place winners will be decided by a double elimination tournament.

If more than 20 teams compete in a division, the division will be divided into groups of up to 16 teams each. The top two robots in each group will be decided by double elimination. The group winners will then compete against each other for the title by double elimination. We use this procedure because one-group double elimination with more than 16 teams becomes too time consuming.

Hints and Tips

This contest requires a light sensor. See Lego robot examples and tutorials for ideas on how to solve this problem.

For some great pictures of Lego Sumo robots that will give you good ideas on building your own robot, visit the web site of the Central Illinois Robotics Club. Look at the Lightweight class and Lego class robots.

Might it be possible to sense the other robot with a touch sensor, then flip it over with a robot arm powered by a third motor? That would really be Sumo!