Mini-Sumo Robot

Contest Description
The Mini-Sumo Robot Contest requires a student team to build a self-propelled, self-controlled, sensing robot, designed to force another Sumo Robot outside a four (4) foot diameter circle. The competition circle will be a flat black, 3’ 6” in diameter, surrounded by a one-inch (1”) wide, painted or taped, flat white ring. Another white one-inch (1”) wide, ring will surround the inner ring with one inch (1”) between them. When any part of the Sumo touches or crosses over the 1” white outer ring it will lose the heat.  For example movie, click picture above


  1. The Sumo must be powered by electrical storage batteries. No other power sources will be allowed. These batteries must be sealed and all possible precautions must be incorporated into design to prevent accidental spills. The judges may disqualify any design that is determined to be unsafe.
  2. The Sumo must use sensing devices to govern the motion of the Sumo and must use sensors to detect the other Sumo and/or the edge of the white circle.
  3. Robots cannot exceed 3 Kilograms in weight.
  4. Robots cannot exceed a maximum size of 20cm x 20cm x 20cm. Any robot entered that does not meet the size requirement by the end of the device evaluation or expands beyond that size during competition will be disqualified. Device evaluation will take place at the time indicated on the Official Schedule.
  5. The Sumo Robot drive wheels must be non-destructive to the playing surface.
  6. The Sumo Robot may not have a remote off/on switch.
  7. Double elimination contests will decide the winner of the contest.
  8. At the beginning of each competition, with the power switch in the “off” position, the Sumo handler(s) will position their Sumo as instructed by the judges. Four start configurations will be possible: At the command of the judge/facilitator, the handler(s) will turn the power switch to the “on” position
  9. When one Sumo causes any part of the other Sumo to go past the outer white circle, that Sumo is declared the winner of that engagement.
  10. If both Sumos leave the circle at the same time, a “non-contest” is declared and the two Sumos are repositioned and the contest begins anew.
  11. If, after two minutes, no winner is declared, the two Sumos are repositioned and
    the contest begins anew. If no winner is declared after this second encounter, the judges shall declare a winner based on action observed within the circle and on the design of the selected Sumo.
  12. A pit area, with access to 110-volt standard outlet, will be provided.
  13. Decisions of the judges are final and binding.


  1. Stage one testing -50 pts (25 pts completion/25 pts individual effort)- must prove that your robot can stay in the black circle and be constantly moving. -50 pts- This stage is tested with one robot in the ring at a time.
  2. Stage two testing – 50 pts (25 pts completion/25 pts individual effort)groups must prove that the have programmed their robots with the ultrasonic sensor to detect and react to objects within their ‘reach’
  3. Stage three – 50 pts-(25 pts completion/25 pts individual effort) Competition!  If time, this will be a double elimination competition.  Robot teams can make any changes at any time (but will NOT have testing time).  1st place will receive an extra 25 pts.  2nd place will get an extra 20 pts.  3rd place will get an extra 15 pts

Tasks You’ll Need to Accomplish?

Note – you don’t have to follow any of the help links below.  Build and program as you will, but be forewarned there will be critical deadlines.


  • Basic Ultra Sonic and Color Sensors
    • Are you using the sensor to ‘see’ the white line?  Compare this to yours
    • Wires connected to the correct ports
    • Check the port assignments on the blocks?
    • Wires pushed all the way in?
    • Sensor responding in ‘Port View?’  If not, switch out wire – give old one to teacher
    • Running the right file?
    • Reset brick