Editing Robot-sumo

{{Short description|Type of robot combat}}
'''Robot-sumo''' ([[Japanese language|Japanese]]: ロボット相撲) is an [[engineering]] and [[robotics]] competition in which two [[robot]]s attempt to push each other out of a circular arena, in a similar fashion to the sport of [[sumo]]. The robots used in this competition are called "sumo robots", "sumobots" or simply "sumos".<ref>[https://www.fsi.co.jp/sumo-e/out/outc0000.html What is Robot-sumo ] in FSI All Japan Robot-Sumo Tournament</ref>

Competitions typically involve autonomously operated [[wheel]]ed [[mobile robot]]s. The [[engineering]] challenges are for the robot to find its opponent (usually accomplished with [[infrared]] or [[ultra-sonic]] [[sensor]]s) and to push it out of the dohyō. A robot should also avoid leaving the arena, usually by means of a sensor that detects the edge.<ref name=":0">{{Cite web |title=ThundeRatz {{!}} Moai |url=https://thunderatz.org/projects/robots/moai |access-date=2024-12-31 |website=thunderatz.org}}</ref> The most common mechanical design is to use a [[wedge]] with a [[blade]] at the front to lift the opposing robot and push it more easily.<ref name=":10" />

[[File:Partida de Sumô de Robôs no Brasil.jpg|thumb|Robot-sumo (Mega Sumo) match in Brazil.<ref name=":0" /> Note the robot on the left being lifted by the opponent's wedge after a direct head-on collision.]]Robot-Sumo originated in [[Japan]] in 1989 when FUJISOFT Inc. <small>[<nowiki/>[[:ja:富士ソフト|jp]]]</small> organized an experimental robot-sumo tournament, which would later be established as the [[Robot-sumo#All Japan Robot-Sumo Tournament|All Japan Robot Sumo Tournament]] <small>[<nowiki/>[[:ja:全日本ロボット相撲大会|jp]]]</small>(Japanese: 全日本ロボット相撲大会 zen'nippon robotto sumou taikai).<ref name=":1" /> Since 1998, FUJISOFT has collaborated with more than 30 countries,<ref>{{Cite web |title=About |url=https://www.fsi.co.jp/sumo/robot/en/about.html#World |access-date=2025-01-22 |website=www.fsi.co.jp}}</ref> and robot-sumo has spread and has been one of the most popular robotics competitions in the world, such as in [[Europe]], [[Mexico]] and [[Brazil]],<ref name=":8" /> with a total of 80,000 people around the world actively developing sumo robots.<ref name=":7" /> Currently, the All Japan Robot-Sumo Tournament is hailed as the "World Robot-Sumo Championship".<ref name=":7" />

Robot-sumo competitions still hold [[amateur]] status, though high-performance competitions (events contested between [[Vocational education|technical students]], [[University|universitarians]] and graduated engineers [[hobby]]ists) require highly complex engineering projects.

Robot-sumo is also often used as an educational tool of engineering, robotics and [[electronics]] for simpler protoypes in schools and [[Undergraduate education|undergraduate]] levels. Sumo robots design has also been the subject of studies and research of [[Academy|academic]] nature as well.<ref>{{Cite journal |last=Torrico |first=César R. C. |last2=Leal |first2=André B. |last3=Watanabe |first3=Ana T. Y. |date=2016-01-01 |title=Modeling and Supervisory Control of Mobile Robots: A Case of a Sumo Robot |url=https://www.sciencedirect.com/science/article/pii/S2405896316328932 |journal=IFAC-PapersOnLine |series=Cyber-Physical & Human-Systems CPHS 2016 |volume=49 |issue=32 |pages=240–245 |doi=10.1016/j.ifacol.2016.12.221 |issn=2405-8963|doi-access=free }}</ref>

== History ==
Robot-Sumo began in [[Japan]] with the [[Robot-sumo#All Japan Robot-Sumo Tournament|All Japan Robot Sumo Tournament]] <small>[<nowiki/>[[:ja:全日本ロボット相撲大会|jp]]]</small> organized by FUJISOFT Inc. <small>[<nowiki/>[[:ja:富士ソフト|jp]]]</small> for the first time in 1989 as an experimental tournament, with 33 participants. The first official edition was established in 1990, and, since then, this tournament has been held annually in [[Tokyo]]. The competition began with an idea from the president of FUJISOFT Inc., Hiroshi Nozawa, whose goal was to promote his company and recruit excellent human resources. But above all, it was because of his desire to give a dream to the younger people who are responsible for the future of his country, and because of the desire to create an environment to improve the quality of "[[Monozukuri]]" in Japan.<ref name=":1">{{Cite web |title=ここに歴史あり｜全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |url=https://www.fsi.co.jp/sumo/history/index.html |access-date=2024-12-31 |website=www.fsi.co.jp}}</ref> Initially, Robot Sumo only included the class that would be later known as Mega Sumo or Sumo 3&nbsp;kg class.

In 1992, the FUJISOFT tournament was held at the [[Ryōgoku Kokugikan]], where the tournament is still held today. In 1998, the tournament had 2,929 participants.<ref name=":1" />

Also in 1998, the first Robot-Sumo competition was held outside of Japan, at the ROBOlympics (later renamed [[RoboGames]]),<ref name=":7">{{Cite web |title=About |url=https://www.fsi.co.jp/sumo/robot/en/about.html |access-date=2025-01-03 |website=www.fsi.co.jp}}</ref> one of the largest robotics events at the time, held in the [[United States|USA]]. This event helped popularize sumo competitions around the world and led to the creation of categories derived from 3&nbsp;kg class, such as Mini Sumo (500g class), [[Lego|LEGO]] Sumo, among others, which further popularized the category as a whole, leading to the emergence of many competitions around the world, such as in [[Mexico]], [[Europe]], and [[South America]]. The exact origin of those derived robot-sumo classes is uncertain, however there are footage of Mini Sumo RC from 2002 at the [[RoboGames]].<ref>{{Cite AV media |url=https://www.youtube.com/watch?v=078U1nd-3Gk&feature=youtu.be |title=2 Hours & Zero Dollars vs. Strobe: RoboGames Remote Control Mini Sumo. 4/2002 |date=2010-02-14 |last=infernolab |access-date=2025-05-22 |via=YouTube}}</ref>

In 2004, at the 15th edition of the All Japan Robot-Sumo Tournament, the tournament introduced the 10&nbsp;kg class, but it would be discontinued in 2007.<ref name=":1" />

In 2008, RoboCore organized the first official national robot-sumo tournament in [[Brazil]] as part of the expansion of the national robotics competition "Winter Challenge",<ref name=":19">{{Cite web |title=RoboCore |url=https://www.robocore.net/eventos/wc4/0}}</ref> originally a [[robot combat]] focused event mainly contested by universitarian teams from the country. In this competition, Sumo 3&nbsp;kg Auto, Sumo 3&nbsp;kg RC and Sumo LEGO classes were held. Until 2019, the Winter or Summer Challenge was the biggest robotics event in Brazil and Latin America, considered the "Brazilian National Robotics Championship" by many.

Also in 2008, with the increasing worldwide popularity of robot-sumo, FUJISOFT held for the first time an edition of the All Japan Robot-Sumo Tournament with international competitors, from [[United States]], [[Mexico]] and [[Singapore]].<ref name=":1" /> Since then, the All Japan became a world championship, with the participation of overseas competitors as “Overseas Representatives”.

In 2010, the Robochallenge, in [[Romania]], hosted a robot-sumo event for the first time.<ref>{{Cite web |title=Robochallenge 2024 |url=https://robochallenge.ro/history/robochallenge-2010 |access-date=2025-01-05 |website=robochallenge.ro}}</ref>

In 2013, FUJISOFT held the first official edition of the International Robot-Sumo Tournament {{NoteTag|Originally the "International Robot-Sumo Tournament 2013" was considered a test event, and was originally called the "International Robot-Sumo Pre-Tournament 2013". Currently, It is listed as part of the International Robot-Sumo Tournament without the status of a "test event".|name=Status of the International Robot-Sumo Tournament 2013}} (Japanese: 世界大会 sekai taikai), separating from the Japanese national All Japan competition (Japanese: 全国大会 zenkoku taikai), with only the best Japanese (champions, and later runners-up) advancing to the world tournament,<ref name=":16">{{Cite web |last=FUJISOFT Inc. |title=RobotSumo2013_leaflet.pdf |url=https://www.fsi.co.jp/sumo/pdf/RobotSumo2013_leaflet.pdf}}</ref><ref name=":25">{{Cite web |last=FUJISOFT Inc. |title=World Robot Sumo Championship Notice of the first INTERNATIONAL ROBOT SUMO TOURNAMENT 2014 to be held concurrently with the 26th All Japan Robot-Sumo Tournament |url=https://www.fsi.co.jp/e/press_release/docs/20141114_INTERNATIONAL%20ROBOT%20SUMO.pdf}}</ref> with both tournaments being held in the same day, in sequence. In this edition, tournament champions or national representatives from [[Austria]], [[United States|USA]], [[Baltic states|Baltic States]] ([[Estonia]], [[Latvia]] and [[Lithuania]]), [[Turkey]], [[Mexico]] and [[Ecuador]] participated as overseas representatives.<ref name=":16" /> The Auto tournament had 16 robots, and the RC tournament, 8 robots, in 2013.<ref name=":25" />

Between 2013 and 2017, without a massive number of Japanese robots (and with a higher number of non-Japanese robots, with some editions reaching more than 100 robots in a single class), non-Japanese international competitors achieved greater results in the International Tournament. European teams achieved significant results in the 3&nbsp;kg Auto class, including top places and championship titles.<ref name=":1" /> In 2017, the last edition of the International Robot-Sumo Tournament was marked by Mexican dominance in the Mega Sumo RC class, taking the first three positions and ahead of the Japanese champions.<ref>{{Cite web |title=全日本の部全国大会｜第29回｜大会結果｜ロボット相撲大会｜全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |url=https://www.fsi.co.jp/sumo/history/record/29/alljapan/index.html#tab |access-date=2024-12-31 |website=www.fsi.co.jp}}</ref>[[File:Brasil no All Japan Robot-Sumo Tournament 2019.jpg|thumb|Parade of Nations in the All Japan Robot-Sumo Tournament 2019.]]In 2018, FUJISOFT reunified the Japanese All Japan competition with the International Tournament into a single tournament, as it was before 2013, retaining the All Japan Robot-Sumo Tournament name and labeling the final stage as the "Grand Final".<ref name=":30">{{Cite web |title=第30回｜大会結果｜ここに歴史あり｜全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |url=https://www.fsi.co.jp/sumo/history/record/30/index.html |access-date=2024-12-31 |website=www.fsi.co.jp}}</ref> In 2019, the competition was in its 31st edition, and had the participation of more than 20 countries, 104 autonomous robots and 78 radio-controlled robots in the Grand Final.<ref>{{Cite web |title=全国大会｜第31回｜大会結果｜ロボット相撲大会｜全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |url=https://www.fsi.co.jp/sumo/history/record/31/alljapan/index.html |access-date=2024-12-31 |website=www.fsi.co.jp}}</ref> With the competition unified again, robots from Japan once again dominated the top positions of the competition in 2018 and 2019.<ref name=":1" /><ref>{{Cite web |title=Previous Results |url=https://www.fsi.co.jp/sumo/robot/en/Results.html |access-date=2025-01-24 |website=www.fsi.co.jp}}</ref>

In 2019, FUJISOFT also organized the first Mini-Sumo event in Japan, as a test event (called pre-tournament) in All Japan, only for Auto category.<ref>{{Cite web |title=第31回｜大会結果｜ここに歴史あり｜全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |url=https://www.fsi.co.jp/sumo/history/record/31/index.html |access-date=2025-01-24 |website=www.fsi.co.jp}}</ref>

In 2020, due to the [[COVID-19 pandemic in Japan]], the 2020 edition (32nd edition) of the All Japan Robot-Sumo Tournament was cancelled.

In Brazil, due to the [[COVID-19 pandemic in Brazil|COVID-19 pandemic]], competitions were also canceled. In response, many teams began organizing remote competitions, in which participants controlled ready-made prototypes provided by the organization remotely through the [[internet]]. For the Robot Sumo category, the most popular was the Remote Mini Sumo RC class, in which participants controlled ready-made robots just like in a conventional competition, but remotely through the internet with a mobile phone application.<ref>{{Cite AV media |url=https://globoplay.globo.com/v/8966121/ |title=Diário TV 2ª Edição {{!}} Mogiano desenvolve tecnologia usada em competição de robôs {{!}} Globoplay |language=pt-br |access-date=2025-01-07 |via=globoplay.globo.com}}</ref> These competitions attracted not only Brazilian competitors, but also international competitors such as Argentines and Indians.<ref name=":3" />

In 2021 and 2022, FUJISOFT organized an alternative competition for the 32nd and 33rd editions remotely for [[Secondary education in Japan|high schoo]]<nowiki/>l competitors (Japanese: 高校学校 koukougakkou), which consisted of a sumo robot design contest.<ref>{{Cite web |title=第32回｜大会結果｜ここに歴史あり｜全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |url=https://www.fsi.co.jp/sumo/history/record/32/index.html |access-date=2024-12-31 |website=www.fsi.co.jp}}</ref><ref>{{Cite web |title=第33回｜大会結果｜ここに歴史あり｜全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |url=https://www.fsi.co.jp/sumo/history/record/33/index.html |access-date=2024-12-31 |website=www.fsi.co.jp}}</ref>

In 2022, RoboCore from [[Brazil]] remodeled its main and largest robotics competition, the "Winter Challenge", into the "RoboCore Experience" (RCX),<ref name=":2">{{Cite web |title=HOME |url=https://www.robocoreexperience.com/ |access-date=2024-12-31 |website=Robocore_XP_CPBR17 |language=pt}}</ref> the largest [[robot combat]] event in [[Latin America]]. The competition hosts the Mega Sumo, Mini Sumo and LEGO Sumo tournaments, jointly with the [[Robot combat|Robot Combat]], Line Follower, Robot Hockey, Robot Trekking, ArtBot and Robot Soccer competitions.<ref name=":3">{{Cite web |title=RoboCore Event Manager |url=https://events.robocore.net/rcx-cpbr14/entries |access-date=2024-12-31 |website=events.robocore.net}}</ref> The RoboCore Experience is held together with [[Campus Party]] Brazil.<ref name=":2" /> The 2023 RCX had 1330 registered competitors and almost 700 robots in all robotics categories.

In 2022, with the end of the COVID-19 pandemic, FUJISOFT once again organized the All Japan Robot-Sumo Tournament (34th edition), but only for local competitors. In the same event, a new pre-tournament for Mini Sumo class was organized by FUJISOFT.<ref name=":13">{{Cite web |title=第34回｜大会結果｜ここに歴史あり｜全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |url=https://www.fsi.co.jp/sumo/history/record/34/index.html |access-date=2024-12-31 |website=www.fsi.co.jp}}</ref>

In 2023, All Japan, in its 35th edition, returned qualifying participants from overseas competitions for Mega Sumo class, for the first time since 2019. This year, the Mini Sumo tournament was officially added to the All Japan, but only for japanese competitors.<ref name=":1" />

In 2024, the robot Senju, from the Sumozade-Era Robotics team from [[Turkey]], became the first non-Japanese Mega Sumo champion of the All Japan Robot-Sumo Tournament since the reunification in 2018, winning in the Auto category.<ref name=":17">{{Cite web |title=全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |url=https://robot-sumo.jp/competition-00ac692d-32df-4199-bc13-6397712d5c2c |access-date=2025-01-05 |website=全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |language=ja}}</ref> Also in 2024, the Mini Sumo of All Japan started qualifying overseas competitors as well. Brazilian teams achieved great success, making the Mini Sumo Auto final, and also taking 2nd and 3rd places in Mini Sumo RC in that year.<ref name=":17" />

In April 2025, FUJISOFT announced that they "will primarily concentrate on the 500g class robots and will reduce participation in the 3kg class for both international and domestic teams", shifting the focus of the All Japan Robot-Sumo Tournament 2025 edition from the Mega Sumo class to the Mini Sumo class. They also announced that "in the future, country representative invitations may not be sent; only teams recognized in official tournaments will qualify for the Grand Final".<ref name=":31">{{Cite web |last=FUJISOFT |title=Instagram {{!}} We are excited to announce that registration for the All Japan Robot Sumo Tournament 2025 edition has officially begun. |url=https://www.instagram.com/p/DITqPLCtTJp/ |access-date=2025-04-18 |website=www.instagram.com}}</ref>

==Rules and Classes==
The principle of a robot-sumo fight consists of two robots competing to push the opponent out of the dohyō. The arena is usually painted with a main color with a contrasting color used to paint a line in the edge (usually, black as the main color and white as the border line color).<ref name=":4" />
[[File:Robot-Sumo Arena-Douhyo.png|thumb|A sketch of a typical robot-sumo arena/dohyō from the All Japan Tournament. The brown lines in the center are called ''shikiri-sen'' ( 仕切り線) and limit the robots initial positioning.]]
Robot-sumo is usually divided in Autonomous (Auto) category, for robots that operate autonomously, and Radio-controlled (RC) category, for robots operated by a person.<ref name=":4" />

In general, the rules may vary in some details from tournament to tournament (arena specifications, starting positioning, handling of exceptions, ...) especially in tournaments of a more educational nature, held in educational institutions as a didactic activity. High level competitions tend to follow standardized rules, such as the rules from [[Robot-sumo#All Japan Robot-Sumo Tournament|All Japan Robot Sumo Tournament]] <small>[<nowiki/>[[:ja:全日本ロボット相撲大会|jp]]].</small>

For example, in FUJISOFT tournaments, matches are typically a series of 3 rounds, with the winner being the one who gets the most round wins. A round usually consists of (1) Positioning, (2) Preparation, and (3) Fight proper. In initial Positioning, a judge signals each operator to position each robot at the same time within the competition's permitted positioning limits. The judge then allows each operator to Prepare to select routines and strategies (in the case of the Auto category) or prepare the remote control (in the case of the RC category). To begin the Fight proper, the judge signals the start of the round according to the competition rules, and the winner of the round is the robot that pushes the opponent out of the arena. In the [[Robot-sumo#All Japan Robot-Sumo Tournament|All Japan Robot Sumo Tournament]] <small>[<nowiki/>[[:ja:全日本ロボット相撲大会|jp]]]</small>, the judge, at the start of a fight, usually announces "Hakkeyoi nokotta" (はっきよい 残った), which can be imprecisely translated as "Ready? Go!".<ref>{{Cite web |title=outc0000.html |url=https://www.fsi.co.jp/sumo-e/out/outc0000.html |access-date=2024-12-31 |website=www.fsi.co.jp}}</ref>[[File:All japan 2018 preparations.jpg|thumb|Competitors preparing the robots before a Mega Sumo fight at All Japan Robot-Sumo Tournament 2018.]]FUJISOFT also requires the usage of a standardized remote controller for the judge in Autonomous category in the [[Robot-sumo#All Japan Robot-Sumo Tournament|All Japan Robot Sumo Tournament]] [[:ja:全日本ロボット相撲大会|<small>[</small>]]<small>[[:ja:全日本ロボット相撲大会|jp]]]</small>  and in its qualifiers Overseas Tournaments, so the judge may control the start and the stop of the robots' movements.<ref name=":4" /> This remote controller uses infrared light with the following specifications: wavelength of 950&nbsp;nm, service frequency: 38–40&nbsp;kHz, and any [[Sony]] brand remote control can be used for the signal. The activation process works with 3 states: Key 1: Ready; Key 2: Start; Key 3: Stop.

Competitions are usually divided into different weight and size classes. The main standardized classes adopted worldwide are Mega Sumo, which is the original robot-sumo class, and Mini Sumo, the most popular variant.<ref>[http://robogames.net/rules/all-sumo.php Unified Robot Sumo Rules (English)]</ref> Though classes have size limits, robots are usually allowed to expand once the fight starts.<ref name=":4" />

=== Mega Sumo ===
Mega Sumo or Sumo 3&nbsp;kg class, also called Standard Class, or simply Robot-Sumo, is the original class created by FUJISOFT. It is currently the most important class and considered the main event of robot sumo competitions.

In this class, robots are limited in weight to 3&nbsp;kg and in dimensions to 20&nbsp;cm x 20&nbsp;cm, with no height limit. Once the fight starts, the robot is allowed to expand its dimensions.<ref name=":4">{{Cite web |title=試合のルール｜全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |url=https://www.fsi.co.jp/sumo/rule/index.html#page2 |access-date=2024-12-31 |website=www.fsi.co.jp}}</ref>

In this class, the dohyō should ideally be a 5&nbsp;cm in height circular aluminum structure with a diameter of 154&nbsp;cm (+/- 50&nbsp;mm), including the border line, and covered by a black cold-rolled steel (SPCC) sheet located on top.<ref name=":4" /> The dohyō is made of steel, and the use of [[magnet]]s is allowed to increase the interaction force between the robot and the arena. Because of this, many robots can achieve normal force values that surpass 100 kgf.<ref name=":9">{{Cite web |title=ThundeRatz {{!}} Stonehenge |url=https://thunderatz.org/projects/robots/stonehenge |access-date=2024-12-31 |website=thunderatz.org}}</ref>

This class is usually divided in Mega Sumo Auto (Autonomous) and Mega Sumo RC (Radio-controlled).<ref name=":4" />

=== Mini Sumo ===
In the  Mini Sumo class (also called Sumo 500g class) robots have a weight limit of up to 500 g and are limited to 10&nbsp;cm x 10&nbsp;cm, with no height limit. Once the fight starts, the robot is allowed to expand its size.<ref name=":4" />[[File:Mini-sumo no Brasil.jpg|thumb|Mini Sumo match.<ref>{{Cite web |title=ThundeRatz {{!}} Ônix |url=https://thunderatz.org/projects/robots/onix |access-date=2024-12-31 |website=thunderatz.org}}</ref>]]The dohyō should be a 2.5&nbsp;cm in height circular wooden board with a diameter of 77&nbsp;cm (including the white border line), covered by a formica laminate located on top. The arena is made of wood, and therefore the robots are not affected by the force of magnets.<ref>{{Cite web |title=Unified Sumo Robot Rules |url=http://robogames.net/rules/all-sumo.php |access-date=2024-12-31 |website=robogames.net}}</ref>

This class is also usually divided in Mini Sumo Auto (Autonomous) and Mini Sumo RC (Radio-controlled).<ref name=":4" />

Since a Mini robot is more affordable than a 3&nbsp;kg robot (due to material costs and manufacturing dimensions), it is a more popular class and often considered entry-level. Because of this, it has become the most popular robot sumo class in the world.

Not an original class from All Japan Robot-Sumo Tournament, the class was added to the tournament as a test event in 2019, and officially added in 2023, introducing mini sumo to japanese builders.<ref name=":13"/>

=== Other Standard Classes ===
There are also other standardized classes in different competitions around the world.
* '''Sumo 10&nbsp;kg class''': up to 10&nbsp;kg, dimensions of 30&nbsp;cm x 30&nbsp;cm, no height limit, steel arena. Class hosted between 2004 and 2007 by All Japan Robot-Sumo Tournament, but currently discontinued.<ref name=":1" />
* '''Micro Sumo''': up to 100 g, must fit in a 5&nbsp;cm cube, wooden arena.<ref name=":15">{{Cite web |title=RoboGames Event Schedule and Rules |url=http://robogames.net/events.php |access-date=2024-12-31 |website=robogames.net}}</ref>
* '''Nano Sumo''': up to 50 g, must fit in a 2.5&nbsp;cm cube, wooden arena.<ref name=":15" />
* '''LEGO Sumo''': robots must be made entirely of [[Lego]] pieces, wooden arena.<ref name=":11">{{Cite web |last=Inatel |title=Sumô Lego - Robótica e IA - Inatel |url=https://inatel.br/robotica/categorias/sumo-lego |access-date=2025-01-03 |website=Robótica e IA |language=pt-br}}</ref>
The Micro and Nano classes are less popular than the Mini and Mega Sumo, but they are held at some relevant events such as [[RoboGames]], RobotChallenge in China, and Robochallenge in Romania.<ref name=":15" /><ref name=":27" /><ref name=":28" />

In the LEGO Sumo class, robots must be made entirely of [[Lego]] pieces.<ref name=":11" /><ref name=":29" /> This class is widely used as an educational tool in schools for teaching robotics.[[File:LEGO Sumo.jpg|thumb|LEGO Sumo match.]]

=== Minor Variants ===
Minor regional competitions might host their own classes as well. Internal competitions in schools might also create their own variants for didatic purposes.<ref>{{Cite web |title=Home {{!}} Lego Sumo Bots |url=https://www.legosumobot.com/ |access-date=2025-01-25 |website=Hackley School |language=en}}</ref>

There are also some robot-sumo events with [[humanoid robot]]s.<ref>{{Cite AV media |url=https://www.youtube.com/watch?v=G4WZB0KQoMg&feature=youtu.be |title=Robot Challenge 2013 - Humanoid sumo - CZ |date=2013-03-29 |last=Tomas Podrabsky |access-date=2025-01-20 |via=YouTube}}</ref>

==== Humanoid robot-sumo ====
[[Humanoid robot|Humanoid]] robot-sumo is similar to [[Robo One|ROBO-ONE]] events.<ref name=":15" /> The robots are generally radio-controlled with some degree of autonomy. The mains robotics events with humanoid robot-sumo featured are the [[RoboGames]],<ref name=":15" /> the chinese RobotChallenge,<ref name=":5" /> and the romanian Robochallenge.<ref name=":20" />

Since this variant involves humanoid robots, it does not follow the same principles of design from the robot-sumo created by FUJISOFT for the All Japan Robot-Sumo Tournament. This category also does not have the same prestige as the wheeled standard robot-sumo classes, such as Mega Sumo and Mini Sumo.

== Robot design ==
Standard sumo robots resemble car-like robots, consisting of a chassis with wheels, and usually equipped with sensors, when with some level of autonomy. The use of mechanisms that physically damage the opposing robot is not usually permitted. For majority of the classes, mainly Mega Sumo and Mini Sumo, a robot design project is usually divided in three disciplines: [[Mechanical engineering|Mechanics]], [[Electronics]], and [[Computer programming|Programming]].<ref name=":10">{{Cite web |title=How to Make a Sumo Robot, Sumo Robot Parts {{!}} JSumo |url=https://blog.jsumo.com/how-to-make-sumo-robot/ |access-date=2025-01-03 |website=blog.jsumo.com}}</ref>

Competitors are encouraged to build their own robots, respecting each competition class' and security rules. In Sumo LEGO, in particular, only [[Lego]] pieces must be used to build the robot, mainly using [[Lego Mindstorms NXT|Mindstorms NXT]] or [[Lego Mindstorms EV3|Mindstorms EV3]] robotics kits.<ref name=":29">{{Cite web |title=ThundeRatz {{!}} Time LEGO |url=https://thunderatz.org/projects/robots/lego |access-date=2025-01-03 |website=thunderatz.org}}</ref><ref name=":11" />

A lot of projects employs electronics components and mechanical parts sold in robotics stores. With the popularization of standardized robot-sumo competitions worldwide, mainly Mega Sumo and Mini Sumo, specialized robot-sumo parts stores appeared, such as JSumo <ref>{{Cite web |title=JSumo Ultimate Robot Parts & Robot Kits Shop for Winners |url=https://www.jsumo.com/ |access-date=2025-01-03 |website=www.jsumo.com/ |language=en}}</ref> and Sumozade,<ref>{{Cite web |title=Sumozade Robotics {{!}} Robot Parts {{!}} Robot Kits {{!}} Robot Shop |url=https://www.sumozade.com/ |access-date=2025-01-03 |website=www.sumozade.com}}</ref> both based in [[Turkey]], which even sell complete Mega Sumo and Mini Sumo robot kits.<ref>{{Cite web |title=Robot Kit Prices {{!}} Mini Sumo Robot Kit {{!}} Sumo Robot Kits {{!}} JSumo |url=https://www.jsumo.com/robot-kits |access-date=2025-01-04 |website=www.jsumo.com/ |language=en}}</ref>

=== Mechanics ===
The [[Mechanical engineering|Mechanics]] consists in the infrastructure that supports and accommodates all the components and systems of the sumobot, including [[Engine|motors]], [[wheel]]s, [[Printed circuit board|PCB]]'s, [[sensor]]s, among others.

A standard sumo robot is wheeled driven robot with a locomotion system. The locomotion system usually consists of driving motors with a coupling system to the wheels, which usually employs a [[Reduction drive|reduction drive system]] to shift the output speed. [[Brushed DC electric motor|Brushed DC motors]] have been the most employed ones,<ref name=":10" /> but there are also robots with [[Brushless DC electric motor|brushless DC motors]].<ref name=":14" /> Motors from [[Maxon Group|Maxon]] or [[:de:Faulhaber (Unternehmen)|Faulhaber]] brands have been popular choices among highest level competitors,<ref name=":10" /> such as robots in the All Japan Robot-Sumo Tournament.

Another commonly employed design for a sumo robot is an angled [[wedge]]/[[Inclined plane|ramp]] in the front of the body. This wedge is usually coupled with a [[blade]] with the purpose of invading the opponent from below and lifting it, so it becomes easier to push it out of the arena.<ref name=":10" />

For Mega Sumo robots, since magnets play an important role in the dynamics performance, the chassis are usually designed to support the desired number of magnets. A builder might choose between a heavier or a lighter robot based on the number of magnets allocated.<ref name=":9" /><ref name=":0" />

Some robot designs also employs peripheral mechanisms. Though classes have dimension limits, they are usually limited to the start of the fight, and once the fight starts, the robot is allowed to expand its size.<ref name=":4" /> Examples of these mechanisms are side flags <ref>{{Cite web |title=Matador Flag System Robot Upgrade Parts Jsumo {{!}} JSumo.com |url=https://www.jsumo.com/matador-flag-system |access-date=2025-01-03 |website=www.jsumo.com/ |language=en}}</ref> and side wedges,<ref name=":26">{{Cite web |title=Instagram |url=https://www.instagram.com/p/DCXbhKVBDUd/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA== |access-date=2025-01-03 |website=www.instagram.com}}</ref> which are usually activated with actuators other than the driving motors.
[[File:Galena Sumo3kg ThundeRatz.jpg|thumb|Mega Sumo Galena, from ThundeRatz <small>[<nowiki/>[[:pt:ThundeRatz|pt]]<nowiki>]</nowiki></small> ([[Polytechnic School of the University of São Paulo|Poli-USP]]), is an example of robot with side blades.<ref name=":26" />]]

=== Electronics ===
In a sumo robot, [[Electronics]] may be divided in two main functions: power supply and logic control.<ref name=":9" /> Sumo robots, in general, employ [[Lithium polymer battery|Lithium polymer batteries]] to supply energy to the motors and other electronic components.<ref name=":10" />

[[Microcontroller]]s are mainly employed to receive data from sensors and send command to the motors and other actuators based on the programmed control logic. Microcontrollers are usually mounted with a designed [[Printed circuit board|PCB]] for the robot.<ref name=":10" />

In Autonomous classes, [[infrared]] sensors or [[Ultrasonic transducer|ultrasonic sensors]] are usually employed to detect the opponent.<ref name=":10" /> Sumos also employ sensors to detect the edge (border line), usually with [[Photodiode|phototransistor]] reflectance sensors.<ref>{{Cite web |title=Ultimate Robot Parts & Robot Kits Shop for Robot Makers |url=https://www.jsumo.com/qtr-8a-line-sensor-analog |access-date=2025-01-03 |website=www.jsumo.com/ |language=en}}</ref>

In RC classes, the robots are remotely controlled by an operator. All Japan Robot-Sumo Tournament usually require [[radio control]]lers,<ref name=":4" /> so the robot hardware must be able to receive commands from the controller using a [[Radio receiver|radio signal receiver]] module.

=== Programming ===
The [[Computer programming|Programming]] discipline is responsible for the [[Embedded system|embbeded]] [[control system]], mainly in the autonomous classes.<ref name=":10" /> A robot-sumo [[firmware]] is responsible monitoring the sensors' data and for controlling the actuators, such as the driving motors.

The robot [[control system]] consists in setting the behaviour of the actuators (mainly the motors) based on the feedback of the sensors. Some usual control routines include setting a behaviour while no opponent is detected, such as randomly advancing through the dohyō, and a behaviour when an opponent is detected, such as pursuing it based on the feedback of the detection sensors.

== Tournaments ==
Currently, several Robot-Sumo tournaments are held around the world. Robot-sumo competitions range from simple didatic and educational tournaments within schools to the highest level engineering competitions between high school/university students, graduate engineers and [[hobby]]ists.

Competitors are usually organized into teams, consisting of the sumo robots themselves and the members responsible for their creation, operation and maintenance during the event. Robot-sumo tournaments still have [[amateur]] status (students and [[hobby]]ists), even though some teams from academic institutions might be guided or leaded by a [[professor]] from the institute, with this advisoring being commonly included as part of his academic activities.<ref>{{Cite web |last=apis3 |title=Equipe Kimauánisso, do Instituto Mauá de Tecnologia, conquista 15 troféus na RoboCore Experience |url=https://maua.br/noticias/press-releases/equipe-kimauanisso-do-instituto-maua-de-tecnologia-conquista-15-trofeus-na-robocore-experience |access-date=2025-01-06 |website=maua.br |language=pt-br}}</ref>

Competitions adopt different competition formats, usually knockout bracket [[Tournament|competitions]], ranging from [[Single-elimination tournament|single elimination]] systems to tournaments with group stage or [[Double-elimination tournament|double elimination]] systems. Teams may register more than one robot per event, and confrontations between robots from the same team are possible.<ref name=":3" /><ref name=":4" />

As for the highest level competitions, Japan is the world's leading powerhouse in this category, and the [[:ja:全日本ロボット相撲大会|All Japan Robot-Sumo Tournament]] is the most prestigious competition in the world, being considered as the "World Robot-Sumo Championship".<ref name=":7" /> Originally a tournament for Japan-based builders, FUJISOFT currently approves several tournaments around the world as certified overseas qualifiers for international competitors.<ref name=":1" />

In Japan, a large portion of the top competitors come from school teams from [[Secondary education in Japan|secondary school]], with tournaments being exclusively held for them. Furthermore, the high school regional qualifiers make up a significant portion of the japanese slots for the All Japan Grand Final.<ref>{{Cite web |title=大会結果｜ここに歴史あり｜全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |url=https://www.fsi.co.jp/sumo/history/record/index.html |access-date=2025-01-20 |website=www.fsi.co.jp}}</ref> In 2024, 66 of the 114 slots for japanese competitors were reserved for high schooler's robots.<ref name=":23" />

Also in Asia, there are also important competitions in China, such as the RobotChallenge,<ref name=":5">{{Cite web |title=首页-RobotChallenge |url=http://robotchallenge.org.cn/ |access-date=2024-12-31 |website=robotchallenge.org.cn}}</ref> and in Mongolia.<ref name=":8" />

In Europe, the RoboChallenge, in Romania, is the main european robot-sumo event, focused mainly on autonomous sumo.<ref name=":28">{{Cite web |title=Robochallenge - Index |url=http://bfrz.ro/en |archive-url=http://web.archive.org/web/20221130072705/http://bfrz.ro/en |archive-date=2022-11-30 |access-date=2024-12-31 |website=bfrz.ro |language=en}}</ref> [[Baltic states|Baltic States]] also organize relevant competitions, such as Robotex.<ref>{{Cite web |title=Robotex International - The biggest robotics festival |url=https://robotex.international/ |access-date=2025-01-26 |website=Robotex International |language=en-US}}</ref>

In the Americas, the former [[RoboGames]], the largest robotics competition in the world at the time, included several Sumo categories in its program, bringing together international competitors from all over the world.<ref name=":15" /> Mexico, one of the world powerhouses, especially in Mega Sumo RC and Mini Sumo, hosts several robot-sumo competitions.<ref name=":8" /> In Brazil, RoboCore hosts and sanctions the main robot competitions of the country, mainly for [[Robot combat|Robot Combat]], but which usually include Robot-Sumo and other events such as Line Follower as well.<ref name=":3" />

=== Japan ===
In Japan, Robot-Sumo is officially sanctioned by FUJISOFT Inc., which organizes the All Japan Robot-Sumo Tournament, the first robot-sumo competition, since 2008 the world's leading competition with robots from over 20 countries participating,<ref name=":1" /> and currently, considered as the "World Robot-Sumo Championship".<ref name=":7" />

Robot-sumo in Japan is also particularly popular among students from the [[Secondary education in Japan|secondary school]]. There are two main tournaments for high schooler's builders: the High Schooler's Robot-Sumo Tournament, organized by FUJISOFT, and the High School Robot-Sumo Championship, organized by AEON Mall, with the support of FUJISOFT, which are also qualifiers to the All Japan Tournament.

==== All Japan Robot-Sumo Tournament ====
{{Infobox tournament|name=All Japan Robot-Sumo Tournament
全日本ロボット相撲大会|game=Robot-Sumo:
- Mega Sumo (Auto and RC)
- Mini Sumo (Auto and RC)|established=1989|administrator=FUJISOFT Inc.|format=Overseas Tournaments: Various
Regional Stage: Single-elimination knockout system
Grand Final: Single-elimination knockout system|venues=Overseas Tournaments: Various outside Japan
Regional Stage: Various in Japan
Grand Final: Ryōgoku Kokugikan, Sumida, Tokyo, Japan|broadcast=Youtube: https://www.youtube.com/@ROBO-SUMO/streams|website=https://www.fsi.co.jp/sumo/index.html}}The All Japan Robot Sumo Tournament <small>[<nowiki/>[[:ja:全日本ロボット相撲大会|jp]]]</small> (Japanese: 全日本ロボット相撲大会 zen'nippon robotto sumou taikai), organized by FUJISOFT Inc. <small>[<nowiki/>[[:ja:富士ソフト|jp]]]</small>, is the official national robot-sumo tournament of [[Japan]]. Founded in 1989, the event is the first robot-sumo event ever, introducing the Mega Sumo class. Since the introduction of overseas participants in 2008, it is considered the "World Robot-Sumo Championship" <ref name=":7" /> for Mega Sumo, both Auto and RC. Since 2023, it has also been officially hosting Mini-Sumo competitions (Auto and RC).<ref name=":1" />

Currenlty, the competition is divided into a "Regional Stage" (Japanese: 地区大会 chiku taikai, [[Literal translation|lit]]: regional tournament) and the "Grand Final"  (Japanese: 全国大会 zenkoku taikai,  [[Literal translation|lit]]: all country tournament), also called "Final Round". The Regional Stage consists of regional tournaments held in Japan between August and October for participants based in Japan, with the top performers from each tournament qualifying for the Grand Final. The Regional Stage tournaments have usually been the [[Kantō region|Kantō]], [[Chūgoku region|Chūgoku]]-[[Shikoku]], [[:ja:北信越地方|Hokushin'etsu]]-[[Tōkai region|Tōkai]], [[Tōhoku region|Tōhoku]], [[Hokkaido|Hokkaidō]], [[Kansai region|Kinki]] and [[Kyushu|Kyūshū]] tournaments, though not all of them may be held every edition. The Regional Stage tournaments currently adopt a single-elimination format and are held in a single day.<ref name=":18">{{Cite web |title=ロボット相撲大会｜全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |url=https://www.fsi.co.jp/sumo/tournament/index.html#page1 |access-date=2025-01-19 |website=www.fsi.co.jp}}</ref> The FUJISOFT's "High Schooler's Tournament" and the "High School Championship" Regional Stage tournaments are also part of regional qualifiers for the All Japan Grand Final.<ref name=":23">{{Cite web |date=2024-12-02 |title=12月7日（土）、8日（日）、全日本ロボット相撲大会2024 決勝大会 “世界一のロボット横綱”を目指して、ロボット力士が両国国技館に集結！ |url=https://prtimes.jp/main/html/rd/p/000000127.000061382.html |access-date=2025-01-22 |website=プレスリリース・ニュースリリース配信シェアNo.1｜PR TIMES |language=ja-JP}}</ref>

International representatives may qualify for the Grand Final through international qualifiers tournaments approved by FUJISOFT, in overseas countries such as [[Mexico]], [[Mongolia]] and [[Brazil]], among others. These tournaments form the "Overseas Tournaments" qualifiers (Japanese: 海外大会枠 kaigai taikai-waku, [[Literal translation|lit]]: overseas tournaments slots).<ref name=":21">{{Cite web |title=ロボット相撲大会｜全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |url=https://www.fsi.co.jp/sumo/tournament/index.html |access-date=2024-12-31 |website=www.fsi.co.jp}}</ref> The Overseas Tournaments are run by different organizations, so the tournament format varies. In some specific cases, qualification certificates are also issued to some teams as "National Representative" or "Country Representative", for countries with no teams yet qualified or without any official qualifier tournament.<ref name=":31" />

The following countries are listed as having already collaborated with All Japan Robot-Sumo Tournament, regarding participation in the tournament or other types of collaboration in robot-sumo:<ref>{{Cite web |last=FUJISOFT Inc. |title=About {{!}} World Map |url=https://www.fsi.co.jp/sumo/robot/en/about.html#World |access-date=2025-04-18 |website=www.fsi.co.jp}}</ref>

* [[Africa]]: [[Democratic Republic of the Congo|DR Congo]], [[Egypt]] and [[Tunisia]].
* [[Asia]]: [[China]], [[Indonesia]], [[Israel]], [[Lebanon]], [[Malaysia]], [[Mongolia]], [[Philippines]], [[Saudi Arabia]], [[Singapore]] and [[Thailand]].
* [[Americas]]: [[Argentina]], [[Brazil]], [[Canada]], [[Chile]], [[Colombia]], [[Ecuador]], [[Mexico]], [[Paraguay]], [[Peru]] and the [[United States]].
* [[Europe]]: [[Estonia]], [[France]], [[Latvia]], [[Lithuania]], [[Poland]], [[Russia]], [[Spain]] and [[Turkey]].

The Grand Final is held in December in [[Tokyo]], [[Japan]] at the [[Ryōgoku Kokugikan]],<ref name=":1" /> and is held in two days, with the first day labeled "Qualification Session" and the final day as the "Grand Final Session" properly.<ref name=":22" /> The Grand Final is also a single-elimination knockout tournament.<ref name=":18" />

Between 2013 and 2017, FUJISOFT split the All Japan Grand Final in the All Japan Tournament properly, which was reserved for japanese competitors, and the "International Robot-Sumo Tournament", a tournament which functioned as the current Grand Final and a proper world championship in name, with the All Japan as the japanese qualifier for the International (similar as other overseas tournaments).{{NoteTag|Originally the "International Robot-Sumo Tournament 2013" was considered a test event, and was originally called the "International Robot-Sumo Pre-Tournament 2013". Currently, It is listed as part of the International Robot-Sumo Tournament without the status of a "test event".|name=Status of the International Robot-Sumo Tournament 2013}}<ref name=":16" /><ref name=":25" /> In 2018, FUJISOFT reunified the competition under the name All Japan Grand Final, which once again functioned as the de facto world championship tournament (even with the "All Japan" in name).<ref name=":30" />

As of 2024, FUJISOFT initially reserved for the All Japan Grand Final, for each of Mega Sumo categories, Auto and RC, a total of 57 slots for the Regional Stage (including the "High Schooler's Tournament" and the "High School Championship" Regional Stage tournaments) and 40 slots for Overseas Tournaments.<ref name=":21" /> While all japanese slots were filled, only 26 and 23 slots were filled by overseas representatives for Auto and RC, respectively. That edition had robots from 17 overseas countries qualified.<ref name=":23" />

==== High Schooler's Robot-Sumo Tournament ====
FUJISOFT also organizes the "High Schooler's Robot-Sumo Tournament" (Japanese: 高校生ロボット相撲大会 kōkōsei robotto sumou taikai). The tournament is exclusive for robots developed by students from [[secondary education in Japan]] (equivalent to [[Secondary school|high school]]) held in parallel with the main [[Robot-sumo#All Japan Robot-Sumo Tournament|All Japan Robot Sumo Tournament]] <small>[<nowiki/>[[:ja:全日本ロボット相撲大会|jp]]]</small>. Like the main All Japan, while initially a Mega Sumo tournament only, the event currently also hosts Mini Sumo tournaments.<ref name=":24">{{Cite web |title=ホーム |url=https://robot-sumo.net/ |access-date=2025-01-19 |website=公式）高等学校ロボット相撲選手権 |language=ja}}</ref><ref>{{Cite web |title=ごあいさつ｜全日本ロボット相撲大会 - ALL JAPAN ROBOT-SUMO TOURNAMENT |url=https://www.fsi.co.jp/sumo/greeting/index.html |access-date=2024-12-31 |website=www.fsi.co.jp}}</ref>

The tournament also consists of Regional Stage tournaments and a Final tournament, with the Regional Stage tournament being usually held jointly with the All Japan Regional Stage tournaments in the same day, while the Final High Schooler's tournament is usually held separately and earlier, in a different venue.<ref name=":18" /> The tournaments also adopt single-elimination format, with the final tournament with 32 robots in each Mega Sumo Auto and RC categories.<ref name=":13" />

The Regional Stage tournaments are also usual qualifiers for the main All Japan Robot-Sumo Tournament Grand Final.<ref name=":23" />

==== High School Robot-Sumo Championship ====
AEON Mall, with the support of FUJISOFT, organizes the "High School Robot-Sumo Championship" (Japanese: 高等学校ロボット相撲選手権 kōtō gakkō robotto sumou senshuken), which is also exclusive to students from [[secondary education in Japan|secondary education]]. Initially a Mega Sumo tournament, the event currently also hosts Mini Sumo class tournaments.<ref name=":24" />

The tournament consists of Regional Stage tournaments only, usually hosted in AEON Mall shopping centres from each host region.<ref name=":24" />

These Regional Stage tournaments are also usual qualifiers for the main [[Robot-sumo#All Japan Robot-Sumo Tournament|All Japan Robot Sumo Tournament]] <small>[<nowiki/>[[:ja:全日本ロボット相撲大会|jp]]]</small> Grand Final.<ref name=":23" />

=== Brazil ===
Widely known for [[robot combat]] competitions, robot-sumo was introduced in [[Brazil]] by RoboCore in 2008 <ref name=":19" /> and has attained increasing attention in the country from 2017 onwards, mainly from teams from the top [[Universities and higher education in Brazil|universities]] of the country. Robot-Sumo has been added to the main robotics competitions contested by teams of engineering and technology students from institutes at [[Education in Brazil#Technical education (ensino técnico)|Technical]] and mainly at [[Higher education Brazil|Higher Education]] levels.<ref>{{Cite web |title=Combate de Robôs no Brasil {{!}} RoboCore |url=https://www.combatederobos.com.br/en |access-date=2025-03-14 |website=combatederobos |language=en}}</ref> Since these teams are mostly students organizations/clubs or research groups, the rotation of members tend to be high, since every year new freshmen get into the school/university, and senior members tend to leave the group after graduation. These teams usually have a [[professor]] from the institute as an advisor, who may contribute for the robots development directly, or be just an representative for internal bureaucracy.

The robotics teams from the [[Polytechnic School of the University of São Paulo|Polytechnic School of the]] [[University of São Paulo]] ([[Polytechnic School of the University of São Paulo|Poli-USP]]), with their team named "ThundeRatz" <small>[<nowiki/>[[:pt:ThundeRatz|pt]]]</small>,  [[Instituto Mauá de Tecnologia]], with their team named "Kimauánisso", and [[Federal University of Rio de Janeiro]] (UFRJ), with their team named "Minervabots", are among the most prominent and successfull robot-sumo teams in the country.<ref>{{Cite web |title=ThundeRatz participa do Mundial de Robótica no Japão – ESCOLA POLITÉCNICA |url=https://www.poli.usp.br/noticias/2675-thunderatz-participa-do-mundial-de-robotica-no-japao.html |access-date=2025-01-19 |language=pt-BR}}</ref><ref>{{Cite web |title=Instagram - É HOJE! Finalmente chegamos ao Japão para competir na @alljapanrobotsumo !! |url=https://www.instagram.com/p/DDPfCvzuYFL/ |access-date=2025-01-19 |website=www.instagram.com}}</ref>[[File:Stonehenge-ThundeRatz.jpg|thumb|Stonehenge, former Mega Sumo RC developed by ThundeRatz <small>[<nowiki/>[[:pt:ThundeRatz|pt]]<nowiki>]</nowiki></small>.<ref name=":9" /><ref name=":14">{{Cite web |title=Stonehenge Robot - ThundeRatz Team » JSumo |url=https://blog.jsumo.com/thunderatz-team-stonehenge-sumo-robot/ |access-date=2025-01-03 |website=blog.jsumo.com}}</ref> Though untypical worldwide, its design was heavily copied by rival teams in Brazil during its active years (2012-2020). As of the IRONCup 2025, it was still the biggest [[:pt:Resultados das Competições de Sumô de Robôs da RoboCore|Sumo 3kg RC RoboCore champion]] and the leader of the History Ranking.<ref name=":262">{{cite web|access-date=2025-02-25 |title=Robot Ranking |url=https://rank.robocore.net/sumo-3kg-rc |website=rank.robocore.net}}<!-- auto-translated from Portuguese by Module:CS1 translator --></ref> ]]These competitions are also open to teams not directly linked with academic institutions, including independent teams of [[Hobby#Hobbyists|hobbyists]], graduated engineers and professionals. These teams are often made up of former students from those academic institutions teams.<ref>{{Cite web |title=Time Raijū de Robótica |url=https://www.instagram.com/raiju.team/ |access-date=2025-01-21 |website=www.instagram.com}}</ref><ref>{{Cite web |title=Equipe Paralela |url=https://www.instagram.com/equipeparalela/ |access-date=2025-01-21 |website=www.instagram.com}}</ref>

Furthermore, international participants, from countries such as [[Ecuador]], [[France]], [[Mexico]], [[Paraguay]] and [[Poland]], have already participated.<ref name=":3" /> Participants from Mexico, one of the robot-sumo world powerhouses, have achieved great success in competitions in Brazil, mainly in Mini Sumo.

==== RoboCore ====
RoboCore is an online store, developer and manufacturer of boards and kits in Brazil and an organizer of robotics events.<ref>{{Cite web |last=RoboCore |title=RoboCore // A loja virtual do maker brasileiro |url=https://www.robocore.net/quem_somos |access-date=2025-01-01 |website=RoboCore |language=pt-BR}}</ref> RoboCore organizes and supports a number of robotics competitions in Brazil, including in its program [[Robot combat|Robot Combat]], Line Follower, Robot Trekking and Robot-Sumo events, attracting mainly universitarian and technical education level teams.<ref name=":3" /> The current major RoboCore robotics competition in general is the RoboCore Experience (RCX, and former Winter/Summer Challenge), the largest [[robot combat]] competition in [[Latin America]], currently held with [[Campus Party]] Brasil.<ref name=":2" />

Currently, the annual calendar competitions from RoboCore with robot-sumo added to their program are the following:<ref name=":3" />

* '''RoboCore Experience (RCX)''': organized by RoboCore, currently held with [[Campus Party]] Brasil. It is usually held at the [[São Paulo]] - [[São Paulo (state)|SP]] edition, which is usually held in July, but it may be hosted in other editions.
* '''IRONCup''': organized by [[Inatel]] and sanctioned by RoboCore, held at [[Santa Rita do Sapucaí]] - [[Minas Gerais|MG]], usually around February/March.
* '''RSM Challenge''': organized by Instituto RSM and sanctioned by RoboCore, held at [[Mogi das Cruzes]] - [[São Paulo (state)|SP]], in the [[Greater São Paulo]], usually around April/May.
* '''RoboChallenge Brasil''': organized by [[Instituto Mauá de Tecnologia]] and sanctioned by RoboCore, held at [[São Caetano do Sul]] - [[São Paulo (state)|SP]], in the [[Greater São Paulo]], usually in October.

The robot-sumo competitions organized or supported by RoboCore are among the most prestigious in the country. RoboCore Experience is the major robotics event in Brazil and considered by many as the brazilian robotics "National Championship". However, the IRONCup, the RSM Challenge and the RoboChallenge Brasil have also become prominent competitions due to their relevance to the brazilian robot-sumo scenario. The RSM has also become prominent as a major international tournament, gathering robots from [[Latin America]] countries, such as [[Mexico]], [[Ecuador]], [[Colombia]] and so on.<ref name=":3" /> Besides these events, some special and once a time competitions might be organized as well.

The classes usually included in RoboCore tournaments program are Sumo 3&nbsp;kg (Mega Sumo) Auto and RC, Mini Sumo Auto and RC and LEGO Sumo. In addition, there is usually a separate LEGO Sumo class exclusively for teams formed by [[Education in Brazil#Elementary school (ensino fundamental)|elementary]] and [[Education in Brazil#High school (ensino médio)|high school]] students, the LEGO Sumo Junior.<ref name=":3" />
[[File:SumôRobô-ThundeRatz.jpg|thumb|Mega Sumo (Sumo 3kg) match between [[Polytechnic School of the University of São Paulo|Poli-USP]] (in the left) and [[Federal Center for Technological Education of Minas Gerais|CEFET-MG]] (in the right) at the RoboCore Winter Challenge 2017.|left]]
RoboCore tournaments usually adopt the [[Double-elimination tournament|double-elimination knockout system]], in which there is a main bracket (called the "winners' bracket") and a secondary bracket of robots transferred after losing a match in the main bracket (called the "losers' bracket"). Robots that lose in the losers bracket are eliminated from the tournament. The tournament final consists of the winner of the winners' bracket competing against the remaining robot from the losers' bracket. Robot-sumo tournaments from RoboCore usually adopt a "double final" format, in which the robot coming from the losers' bracket must win two matches of the final to become the tournament champion, while the robot coming from the winners' bracket must win only one match. This is due to the principle that for a robot to be eliminated, it must suffer two defeats in the event.

RoboCore calendar robot-sumo events (RCX, IRONCup, RSM Challenge and Robochallenge) have been usually approved by FUJISOFT as "Overseas Tournaments" qualifiers for the [[Robot-sumo#All Japan Robot-Sumo Tournament|All Japan Robot Sumo Tournament]] <small>[<nowiki/>[[:ja:全日本ロボット相撲大会|jp]]]</small> in the Mega Sumo and Mini Sumo classes.<ref name=":8" /> Thus, these competitions are the main qualification path for teams based in Brazil.

RoboCore also organizes the "RoboCore's Robot History Ranking", a historical ranking of registered and participant robots in RoboCore tournaments, including those in the robot-sumo classes. The system is based on the [[Elo rating system|Elo system]] that calculates the relative strength between opponents based on the result of each confrontation. The RoboCore system adopts an initial score of 1200,<ref>{{cite web|access-date=2025-02-25 |title=Robot Ranking |url=https://rank.robocore.net/about |website=rank.robocore.net}}<!-- auto-translated from Portuguese by Module:CS1 translator --></ref> but does not exclude inactive robots from the ranking. Since the system is tied to a registered robot, then the ranking is compiled exclusively for each instance registered in the system (this means if a robot is registered with different labels for different tournaments, the ranking will be compiled for each label, as different robots). For robot-sumo, the RoboCore ranking is compiled for the major classes in Brazil: Sumo 3&nbsp;kg Auto, 3&nbsp;kg RC, Mini Auto, Mini RC, LEGO and LEGO Jr., but also for minor classes, such as the remote classes, popular during the [[COVID-19 pandemic]].

==== Other tournaments in Brazil ====
Though RoboCore organizes and sanctions a number of events, most of them are hosted in the [[Southeast Region, Brazil|Southeast]] region of Brazil, mainly in the [[São Paulo (state)|São Paulo state]]. Different academic institutions have also been organizing regional tournaments, mainly in the [[Northeast Region, Brazil|Northeast]] and [[South Region, Brazil|South]] regions of Brazil.

From 2017 until 2021, [[Instituto Mauá de Tecnologia|Instituto Mauá]] also organized additional tournaments in São Paulo state in partnership with [[:pt:Serviço Social do Comércio|SESC]], from [[Santo André, São Paulo|Santo André]] in the [[Greater São Paulo]], and with [[Bosch (company)|Bosch]] Brazil in [[Campinas]] - [[São Paulo (state)|SP]]. These tournaments were also added as Overseas Tournament qualifiers for the All Japan Robot-Sumo Tournament.

=== China ===
[[China]] hosts the RobotChallenge.<ref name=":5" />

==== RobotChallenge ====
The RobotChallenge is "one of the world’s largest artificial intelligent robotic championships" and had the participation of more than 80 countries through the years.<ref name=":5" /> The competitions hosts a number of robotics competition such as Air Race, Line Follower, Humanoid Sprint and RoboSumo (Robot-Sumo).<ref name=":5" />

For Robot-sumo, the competition organizes tournaments for Mega Sumo, Mini Sumo, Micro Sumo, Nano Sumo and Lego Sumo classes.<ref name=":27">{{Cite web |title=相扑赛-RobotChallenge |url=http://www.robotchallenge.org.cn/competition-RobotSumo.html |access-date=2025-01-02 |website=www.robotchallenge.org.cn}}</ref> There is also a special class for Humanoid Sumo.

RobotChallenge is also a usual Overseas Tournament qualifier for the All Japan Robot-Sumo Tournament.<ref name=":8" />

=== Mexico ===
[[Mexico]] hosts a number of robot-sumo events. The prominent ones are usual approved Overseas Tournaments qualifiers for the All Japan Robot-Sumo Tournament.<ref name=":8">{{Cite web |title=Instagram - ALL JAPAN ROBOT SUMO |url=https://www.instagram.com/p/C-X-fwuKRkB/ |access-date=2025-01-02 |website=www.instagram.com}}</ref>

=== Mongolia ===
[[Mongolia]] hosts a number of robot-sumo events. The prominent ones are usual approved Overseas Tournaments qualifiers for the All Japan Robot-Sumo Tournament.<ref name=":8" />

=== Romania ===
[[Romania]] hosts the Robochallenge.<ref name=":20">{{Cite web |title=Robochallenge 2024 |url=https://robochallenge.ro/ |access-date=2025-01-02 |website=robochallenge.ro}}</ref>

==== Robochallenge ====
Robochallenge was first organized in 2008, and initially called ROBOT FOTBAL, hosting a Robot Football competition.<ref>{{Cite web |title=Robochallenge 2024 |url=https://robochallenge.ro/history/robochallenge-2008 |access-date=2025-01-02 |website=robochallenge.ro}}</ref> It currently organizes tournaments of Line Follower, Robot Football, Maze, [[Robot combat|Robot Combat]] and Robot-Sumo, among others.<ref name=":6">{{Cite web |title=Robochallenge 2024 |url=https://robochallenge.ro/regulation |access-date=2025-01-02 |website=robochallenge.ro}}</ref> The competition is held at [[Politehnica University of Bucharest|Politehnica of Bucharest]].<ref>{{Cite web |title=Robochallenge 2024 |url=https://robochallenge.ro/contact |access-date=2025-01-02 |website=robochallenge.ro}}</ref>

As of 2024, the robot-sumo classes hosted by Robochallenge Romania are Mega Sumo, Mini Sumo, Micro Sumo, Nano Sumo.<ref name=":6" /> It also organizes a Humanoid Sumo competition.

Robochallenge is an also usual Overseas Tournament qualifier for the All Japan Robot-Sumo Tournament.<ref name=":8" />

=== United States ===
The [[RoboGames]] is held in the [[United States|USA]],<ref>{{Cite web |title=RoboGames! (formerly ROBOlympics) |url=https://robogames.net/index.php |access-date=2025-01-03 |website=robogames.net}}</ref> which was, until 2016, the largest open robotics competition in the world.<ref>{{Cite news |date=2016-04-27 |title=Robotics tournament VEX Worlds is named largest in the world after 1,075 teams take part |url=http://www.guinnessworldrecords.com/news/2016/4/robotics-tournament-vex-worlds-is-named-largest-in-the-world-after-1-075-teams-ta-426576 |archive-url=http://web.archive.org/web/20240614003154/https://www.guinnessworldrecords.com/news/2016/4/robotics-tournament-vex-worlds-is-named-largest-in-the-world-after-1-075-teams-ta-426576 |archive-date=2024-06-14 |access-date=2025-01-03 |work=Guinness World Records |language=en-GB}}</ref>

==== RoboGames ====
{{Main|RoboGames}}
RoboGames is an international robot event contested annually in the USA. The events are divided in categories: Humanoids; Auton. Humanoid Challenges; [[Robot combat|Combat]]; Robot Soccer; Open; Jr League; Autonomous Autos; Art Bots; BEAM, and Sumo.<ref name=":12" /> It hosted the first robot-sumo event outside Japan, in 1998.<ref name=":7" />

As of 2024, RoboGames opened registrations for the following robot-sumo events: Nano 25g (auton), Micro 100g (auton), Mini 500g (auton), Mini 500g (junior class), 1&nbsp;kg (kit-auton), Mega 3&nbsp;kg (R/C), Mega 3&nbsp;kg (auton), 4&nbsp;kg (Humanoid).<ref name=":12">{{Cite web |title=RoboGames Event Schedule and Rules |url=https://robogames.net/events.php |access-date=2025-01-03 |website=robogames.net}}</ref>

RoboGames is an also usual Overseas Tournament qualifier for the All Japan Robot-Sumo Tournament.<ref name=":8" />

== In the media ==
The popular [[internet meme]] [[Kenshiro#Internet memes|"Omae wa mou shindeiru"]] (お前はもう死んでいる, English: You are already dead), from Japanese manga series ''[[Fist of the North Star]]'', has been adapted to robot-sumo fight videos and became viral. A video uploaded on [[YouTube]] in 2017 by the user "Sh0gun", named "[https://www.youtube.com/watch?v=0MW0mDZysxc *teleports behind you*]", has gathered more than 63 million visualizations.<ref>{{Cite AV media |url=https://www.youtube.com/watch?v=0MW0mDZysxc |title=*teleports behind you* |date=2017-06-20 |last=Sh0gun |access-date=2025-01-04 |via=YouTube}}</ref>

In 2018, Japanese robot-sumo has been the subject of a short video from [[Great Big Story]] named "[https://www.youtube.com/watch?v=mS-L2fpV1Is The Freakishly Fast World of Robot Sumo]" released on [[YouTube]].<ref>{{Cite AV media |url=https://www.youtube.com/watch?v=mS-L2fpV1Is |title=The Freakishly Fast World of Robot Sumo |date=2018-01-24 |last=Great Big Story |access-date=2025-01-01 |via=YouTube}}</ref>

Since 2019, FUJISOFT has been live transmitting the Regional Stage and the Grand Final tournaments of All Japan Robot-Sumo Tournament on a [https://www.youtube.com/@ROBO-SUMO dedicated Youtube channel].<ref name=":22">{{Cite web |title=全日本ロボット相撲大会 |url=https://www.youtube.com/@ROBO-SUMO/streams |access-date=2025-01-01 |website=YouTube |language=en}}</ref>

== Notes ==
{{reflist|group=note}}

== See also ==

* [[Robotics]]
* [[Robot competition]]
* [[Robot combat|Robot Combat]], a related robot competition
* [[Sumo]], the traditional Japanese martial art that inspired robot-sumo

==References==
{{Reflist}}

==External links==
{{Commons}}

===Tournaments===
*[https://www.fsi.co.jp/sumo/index.html All Japan Robot-Sumo Tournament] The first robot-sumo event and now considered as the "World Robot-Sumo Championship".
*[http://robogames.net/ International RoboGames] International tournament held in California, USA which was once the largest robotics open event in the world.
*[https://www.combatederobos.com.br/en RoboCore] Main robotics competitions organizer in [[Brazil]]. Hosts the Robocore Experience (RCX), the biggest competition in [[Latin America]], among other tournaments.
*[http://www.robochallenge.ro/ RoboChallenge] Robotics competition held in Bucharest, Romania.

=== Competitor Teams ===

* [https://thunderatz.org/ ThundeRatz] Robotics team from [[Polytechnic School of the University of São Paulo|Polytechnic School of the]] [[University of São Paulo]], Brazil.

=== Miscellaneous ===

* [http://www.jsumo.com/ JSumo] Turkish robotics store specializing in Robot-Sumo
* [http://www.robotroom.com/SumoRules.html RobotRoom] Tutorial
*[http://www.societyofrobots.com/robot_tutorial.shtml Robot Tutorials for Beginners] Tutorial

[[Category:Robot combat]]
[[Category:Sumo]]
[[Category:Robotics]]
[[Category:Robotics competitions]]