Objective of RoboSumo is simple: Push the other robot out of the Sumo ring.
Robot Sumo is now the most popular robot competition worldwide.
Robofest Age Divisions
- Junior Division for grades 5 - 9
- Senior Division for grades 9 -12
| || Junior Division
|| Senior Division|
| Sumo ring diameter
|| 77 cm (30 inches)
|| 122 cm (48 in)
| Maximum robot mass
1kg (2.2 lbs)|| 2 kg (4.4 lbs)|
Maximum robot width and length
|| 23 cm (9.0 inches)||
30 cm (11.75 inches)|
| Maximum robot height
|| no limit
|| 30 cm
| Robot type
|| Lego Mindstorms RCX or NXT only.
The Sumo ring is made of flat black painted plywood or MDF board. There is a 5
cm wide white painted border. Recommended height from the floor is around 5cm. A
detailed instruction, though the spec is slightly different from that of
Robofest RoboSumo, can be found on the web at:
The robots must be totally autonomous (computer brains on board) meaning, no
remote control or human intervention of any kind, and no tethered, IR, or RF
connection to a host computer. You may use any number of motors. You may use any
type/number of sensors.
- Junior Division - only LEGO Mindstorm RCX or NXT is allowed. Parts are
limited to any official or compatible Lego Mindstorms or Mindstorms NXT
piece, rubber bands, removable tape, cardboard, etc. Not allowed: glue,
anything that damages the Lego parts, vacuum or sticky wheels.
- Senior Division - any type of autonomous robot is allowed, including
kits and custom-built robots. Vacuum or sticky wheels are not allowed.
Sumo 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, the judge will randomly determine which way
to orient the robots. The players will then place their robots in the
indicated positions as illustrated below. Team A will be considered as the
team to the judge's left and Team B to the judge's right.
- How to start a game is unknown. It will be unveiled on the day of
the competition. Students must complete the unknown challenge that will
require a touch sensor or a downward facing light sensor.
An example of the
unknown start problem would be: (1) The robot must wait until touch sensor
is pressed (2) After detecting the touched sensor, wait for 5 seconds then
start to move.
No adult help is allowed to complete this part. If this
unknown challenge is not done, the robot is automatically disqualified.
However, the site host may arrange special matches for those teams who did
not solve unknown challenge. (They are not considered for World
- When the game is started, both players should 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 judges will activate the robots using the unknown challenge.
- 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:
- Both robots are locked together and stop movements for 30 seconds,
or are stuck in the a repetitive pattern for 30 seconds.
- Both robots move or stop for 30 seconds without touching each other.
- 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.
Last updated: January 21th, 2008
Robofest Home: www.robofest.net