The Mega Sumo category is the most spectacular category of robots, two robots are placed on a 1.5m diameter steel ring, where they fight autonomously against each other until one is removed from the ring.
Each robot of mega sumo must be within the 3 kg weight limit and in the size of 200 x 200mm. The robot must be fully autonomous and be able to start and stop on command from the referee via star/stop module (see appendix in the regulations).

1. General information

The matches will take place between two teams, each team having one or more members. During the battles only one member may approach the ring, the other team members must watch the match from the public. According to the rules, the teams will compete in a Dohyo (sumo ring) with an autonomous robot of their own creation as specified in Section 2.
The referee designate the start of the match with the remote control, and it continues until one of the two robots get 2 points "Yuhkoh". The referee designates the winner.

2. The implementation of the robots

2.1. The building of the robot
A. It accepts any design which does not fall under the limitations of chapter 2.2.
B. Maximum dimensions: the robot must fit in a square 20cm x 20cm.
C. The maximum mass of the robot must not exceed 3.00 kg.
D. After the beginning of the round, the robot can expand. The robot is not allowed to separate into two or more pieces. He must remain in a single centralized robot. The robots that do not respect these rules will be disqualified.Screws, nuts, washers or other parts that weigh less than 5 grams that will fall, will not result in losing the match.
E. All robots must be autonomous. Any control systemIt can be implemented, while it is inside the robot and does not interact with external control systems (human, machine or another).

2.2. Limitations of the robot
A. For safety reasons the robots must be equipped with a sensor module on/off (infrared) which will be operated by the judges. When the referee sends a stop signal, the supply of the engines has to be cut. The sensor will be used also to simultaneously power both robots, by the referee. The specifications for the sensor on/off IR are in Appendix 1.
B. Jamming devices that can be used against opponents such as radiation sources to saturate IR sensors, ultrasonic transmitters or other devices with similar effect are strictly prohibited.
C. Components of the robot that can destroy the playing area are not allowed. Do not use components intended to destroy the opponent's robot. The thrusts and the normal blows specific for a sumo match, are not considered intentions for destruction.
D. Devices that can store liquid, powder, gas or other substances that could be thrown into the opposing robot are prohibited.
E. Any devices that throw flames are not allowed.
F. Any devices that throw objects towards the opponent are not allowed.
G. The sticky substances that can improve the traction are not allowed. The wheels and other components of the robot that are in contact with the floor shouldn’t be able to raise and support a standard A4 sheet (80mg / m²) for more than 2 seconds. The robots will be checked in the homologation phase and it can be verified again at the request of the referee in any stage of the competition.
H. Devices for increasing pressure on the surface, such as vacuum pumps or magnets / electromagnets are allowed.
I. The blade of the robot and the expansion cannot be white.
J. It is allowed to use a maximum of 2 flags on the robot. The flags must be upright and be within the perimeter of the robot. They may fall after the start of the match.

3. Dohyo (sumo ring)

3.1. The inside of the ring
The inside of the ring is defined as the playing surrounded surface, but which includes the white line. Any area outside the ring will be called outside the ring.
3.2. The specification of the ring
A.The play area is defined as a steel disk with thickness between 3 and 5 mm with black colour, with a diameter of 154cm.
B. The ring is placed on a metal support and it is lifted up to 5 cm above the ground.
C. Around the ring there is a clearance space so that the sensors of the robots are not disturbed.
D. Dimension of the ring allows a tolerance of 5%.
3.3. The outside of the ring
There is a safe space outside the ring. This space can be any color, can be of any material and may have any shape. This zone with the ring in its center will be called the zone of the ring. The zone typically is a square with sides of 4 meters.

4. Course of the match

4.1. A match consists of three rounds, each lasting a maximum of 3 minutes with the possibility of extending the time by referees.
4.2. The first team that wins two rounds or receives the first two points "Yuhkoh" until the end of the time will win the match. A team receives one point "Yuhkoh" when they win a round. If the time limit is reached before a team receiving two points "Yuhkoh" and one team received a "Yuhkoh", the team with a point will win.
4.3. If the game is not won by any team in the time limit, an additional round will be played. After exhausting all alternatives, the winner of the match can be decided by arbitrators by lot or other criteria established by the arbitration panel.
4.4. If the robots crash they will be stopped after 2 seconds and the game will resume. If after the 2nd attempt the robots crash again, it will be called equality.
5.5. If one of the two robots are not going to the start, there will be a restart. If after a restart the same robot does not work the match will be won by the functional robot. (Participants are required to notify the referees at the start of the match if the robot has a sequence that does not start after the received signal, which should not be confused with a malfunction).

5. The progress of the contest

5.1. The robots will be divided into groups according to the number of participants. The contest will run in this system, groups / quarters / semifinals / final to allow as many rounds of play for each robot separately. Each match goes in this system as the best of three rounds and will be supervised by two referees (one referee and one assistant referee), excepting the final, where the game will be played in the format ''the best of 5 rounds''. The referee's decision must be unanimous and final, and contesting his decision brings the participants disqualification from the match.
5.2. Throughout the competition a team is allowed to have two interruptions for reprogramming during matches, 5 minutes each (2 outages throughout the contest). Other breaks are only allowed for mechanical problems and only with the referee approval, with 5 minutes each. This rule is only applied when performing a match. Outside the matches, the reprogramming and the changes are allowed. Teams are required to be to the starting point in maximum 1 minute of receiving the request, otherwise they will lose the match.
5.3. After approval, all teams remain in the competition hall. The teams can leave the room only for repairs. If a team leaves the room for repair, it must turn during specified by the referee. If the robot is not present at the first call, the team loses the match.

6. Homologation

The homologation will take place at the beginning of the sample.
Each team will have to pass the homologation stage to participate with the robot in the contest.
Stages of the homologation process are:
6.1. Verification of the dimensions of the robot by placing a box/frame of 20.3 x 20.3 cm, bottomless, over the robot.
6.2. Weighing the robot on a digital scale. The maximum recorded weighing should be of 3.005 kilograms.
6.3. Will be Checked operation of the IR sensor to start and stop the robot.
The robot will not be retained after homologation.
After homologation of all robots, the teams remain mandatory in the examination room / competition area.

7. The score

A "Yuhkoh" will be granted when:
7.1.The robot of a team forces the opponent to get out of the ring by pushing or lifting. The robot of the opponent is considered defeated if it touches any part or components, which is placed on the outer surface of the ring.
7.2.The robot opponent gets out of the ring for any reason.
7.3.The opponent robot breaks, without possibility to continue the round and the team representative announces this.
When determining the winner falls to the referees after exhausting specific criteria Sumo competition, the following aspects are taken into account:
A. Quality of the construction and programming of the robot.
B. Penalty points accumulated during the match.
C. The attitude of the team during the match.

8. Start, Stop, Restart, End and duration of match

8.1. The start position of the robot.
At the Instructions of the referees, both teams are approaching the ring to put robots on the contest area. A cross with two opposing arrows placed in the middle, divides the sumo ring into four quadrants . Robots always must be placed in two opposite quadrants. The robots must be placed at the edge of the assigned quadrant. Robots must cover at least partially the white edge. After positioning the robots and the cross is removed the robots can’t be manually moved anymore.
8.2. Start
The start is given by the referee in each round using a remote control that sends a signal to the robot, where both of them will begin immediately without any delay. The details of the sensor can be found in the annex.
8.3. Stop, Continue the match
Start, interruption or continuation of the match are announced by the referee.
8.4. End of the game.
When the referee announces the end of the game, the two teams raise their robots from the ring.
8.5. The duration
A match will be played over 3 minutes. It will start and end at the referee's command.
8.6. Extension
If an additional match is requested by the referee, it will take up to 3 minutes.
8.7. The game is stopped and the round is resumed in the moment when:
A. The robots revolve around each other, without visible progress for 10 seconds. Robots are stranded for more than 2 seconds. If it is not clear that the robot is progressing, the observation time can be extended up to 30 seconds.
B. The both robots are moving without making any progress, they stop (while) or they stay still for 10 seconds without touching themselves. However, if a robot stops moving, after 10 seconds it will be declared defeated without fighting initiative. In this case the opponent will receive a "Yuhkoh" even if he stopped. If both robots are moving, but progress is not clear, the referees may extend the observation time to 30 seconds.
C. If both robots touch the outer surface of the ring at the same time and it can not be determined which robot reached the outer surface first, the round will be replayed.
8.8. Repairs, modifications, sudden interruption
If a robot is damaged during a match, the referee shall allocate an interval of 1 minute for repairs. This range may be extended up to 5 minutes by the organizers. Repairs will be supervised by an assistant referee to avoid change of unapproved other robot modules.
If a robot can't be repaired within the specified interval, the match is won by the opponent robot, and the team with the broken robot can continue the repairs until their next match and they will be supervised by a referee or a member of the organizing committee.
Replacing the defective parts can be performed, and the batteries can be charged during the competition, if it’s necessary.

9. Accidents during a match

9.1 The request to stop a match
A contestant can ask for the end of the match if he/she is injured or the robot sustained damage and cannot continue the game.
9.2. Unable to continue the match
When the game cannot continue due to injury or because of the damage to the robot, the contestant who caused the injury or malfunction of the robot will lose the match. If the referee cannot decide who is guilty then who has asked to stop the match will be declared defeated.
9.3. The time required to care / repair
If the game can continue, in case of injury or damage, it will be decided by arbitrators.
The decision must be taken within 5 minutes.