How it all started

A few years ago, a friend of mine invited me to a robot competition held at the Technical University of Cluj-Napoca. There, at the BattleLab Robotica contest I saw sumo robots for the first time. I liked the idea so much that I promised I would come back the next year as a participant. So I started working at my first sumo robot together with a few colleagues from the university. I was very surprised and happy to see that we have a local community of robot builders.

The competitions

Sumo robots are one of the common types used in international competitions, along with line followers, maze solvers, etc. During a match, two autonomous robots fight on a metal ring, trying to push the other one off the ring.

Why?

I think there are a few great things that come with building such a robot. What drives me the most is having a challenge to solve using my knowledge. My first projects as a hobbyist involved recreating basic ‘hello world’ like electronic circuits or algorithms. After a while, I needed a new kind of challenge to make me feel like I’m making progress. A sumo robot felt like the best next level project in this stage because it involves mechanical, software and hardware components that need to interact perfectly.

Also, I tend not to finish my personal projects if things don’t seem to be going well in their initial stages. In this situation, having precise specifications and a team to help during tough times certainly helps. Also due to the fact that the robots are quite expensive, the project is funded by sponsors and this gives me the opportunity to work with industrial components that I wouldn’t afford. Moreover, international competitions are great opportunities for knowledge sharing because other participants have similar interests.

The competition in Tokyo

There are also non-technical benefits involved in this hobby and one of them is travelling. So far I only got the chance to take part in one international competition abroad, but it was the biggest of its type : the All Japan Robot-Sumo Tournament in Tokyo. It was such an intense experience for me that summing it up is really hard, but here are the main things that struck me.

I had about 3 days to visit the city. I saw the main tourist attractions, but the thing that impressed me the most was the huge culture difference compared to what I grew up with. Just being there felt a lot different. People were a lot quieter and a lot more polite which sometimes caused the locals to look at us like we were doing something wrong.

The competition itself, All Japan Robot-Sumo Tournament took place at the Ryogoku Sumo Hall, where real sumo tournaments take place. Here, the Fujisoft CEO (the company that organizes the contest) started his speech by mentioning the Japanese word ‘monozukuri’, which roughly translates to ‘the spirit of making things’. He outlined the importance of this word in Japanese culture and encouraged all the participants to keep this spirit alive. I was also impressed by the fact that the robot sumo matches share parts of the real sumo ceremony. The opponents have to salute each other by leaning forward. The referee counts down the exact moment that the robots have to be put on the ring. He starts the match with the phrase used in real sumo, ‘hakkeyoi nokotta’.

Conclusion

After the competition we had some friendly matches. This was a great opportunity for sharing knowledge with the best sumo robot builders in the world, who were very open at giving away some technical know-how. Back home I started assimilating the whole experience. After the cultural shock was gone, I began to improve my robot based on what I saw in Japan. Now it feels like building such robots is a never ending task. There will always be room for improvement. At least now I know what I should consider in order to stay competitive.