iRobo Sumo
The rulebook.
Sumo tests engineering design, programming and strategy: two autonomous robots try to push each other out of a circular ring.
At a glance
- Alllevel
- Teamcontest type
- 2–3students per team
- 3teams per centre
- iRobosponsor
Materials
Allowed
- LEGO EV3, NXT, VEX or other robotic systems
- Mechanical parts made of plastic, metal or wood
- Rubber bands, string, wheels, gears and pulleys
Metal parts such as VEX are allowed but may push you over the weight limit.
Not allowed
- Sharp or pointed edges
- Strong magnets and liquids
- Shooting parts, flames or anything flammable
- Anything that could interfere with other robots, such as jammers
- Remote control of your own robot
- Glued LEGO or other parts
The host centre provides
- Sumo board
- Stopwatch
- Elimination chart
- Scale up to 2 kg, 1 g precision
- 30 × 30 cm test square
The rules
Eleven points every team should know before the first match.
Safety first: robots must not endanger competitors, other robots or the ring. No sharp parts, nothing that shoots or flies off.
The ring is 36″ (about 91 cm) across and ¾″ thick: a 32″ black circle with a 2″ white border. It sits on a level surface.
Teams are drawn at random into a single-elimination chart or a round robin. At least one team member must be present for each match.
Each team places its own robot in the ring: opposite sides, facing any direction. Sides switch after every round.
After “On your marks, get set, go”, teams start their robots. Robots wait 5 seconds before moving.
Pushing, shoving and knocking over are allowed to force the opponent out of the ring.
Push the other robot out and you win the round. If both fall out, the first one out loses. If any part touches the floor outside the ring, that robot loses the round.
A round lasts 1 minute. Win 2 of 3 rounds to advance. No winner after 1 minute is a draw; the judges may repeat the round.
If robots get entangled or stuck in a long pushing match, the judge stops the bout and resets both to their starting positions.
Nobody touches the robots or the ring during a match. Everyone stays 1 metre away so sensors are not disturbed.
Between rounds only the kids make repairs, no adults. Changing programs is fine, delaying is not: holding up a match can mean forfeiting it.
Judging
Spec check
Before the start, judges check every robot’s weight, size and safety. Then they draw the chart with as few byes as possible.
How judges run it
- Several judges watch for the moment a robot leaves the ring.
- A separate judge keeps time and stops the clock when robots need separating.
- Repairs are quick: at most 2 minutes of waiting between rounds or matches.
- A draw is settled by an extra round.
Tournament format
Single elimination
Winners move up the chart. Losers are out.
Round robin
Every team plays every other team. The most wins decide places 1 to 3.
