I have been planning to write this article for a long time. So, I am really happy to finally get it posted and welcome everyone to the world of Lego Sumo Wrestling Robots (aka SumoBots).
You probably know that I have been mentoring robotics for the students at All Saints College in Perth for many years now. My kids are all grown up, have completed university degrees and have been working full time in industry for a few years already, but I love helping the engineers of tomorrow get excited about building and programming robots. I explained more in my previous article:
At the robotics club, we start the younger (Year 5) students’ robotics journey by introducing them to building Lego Mindstorms robots to compete in a Sumo Wrestling competition.
We give the students a couple of terms to build and test their robots. As the software is already written and provided for them, they can concentrate on building strong robots with low centres of gravity and good pushing power. The robots can be wheeled or tracked and it is up to the students to design and decorate them as they wish. There is a setup program which the students can configure to work correctly for their build and adjust some of the behaviour of the robots.
Eventually, we hold a competition, which is always a very noisy and lively day with the students cheering their robots on.
The wrestling itself is held on 1m diameter white circular board with a 3cm black painted edge, raised on 4 wooden blocks. The robots start in the middle with their drive wheels either side of the centre of the ring pointing in opposite directions. The round begins by starting the programs on both robots at the same time and the battle commences after a 5 second countdown. Whichever robot is pushed out of the circle and off the board first loses.
Here are some hints for building the robots:
- Make sure the robots are strong, solid and don’t fall apart.
- Make sure that the wheels or tracks grip well.
- Point the light/colour sensors down with about a gap of a finger width to the ground.
- Make sure that the light/colour sensors are in front of the wheels as they detect the black edge and stop the robots driving off the edge of the board.
- For the robots to “see” their opponent, you can use an Ultrasonic or Infrared (EV3 only) sensor (which has a longer range, but cannot provide directional data), or better, use the SumoEyes sensor for Mindsensors.com (which has a shorter range, but can provide directional data).
- Make sure that the Ultrasonic/Infrared/SumoEyes sensor is pointing forward and not upwards or downwards at the ground.
After the SumoBot competition, now armed with their building skills, we move the students on to the Robocup Junior Australia competition, into the Onstage Performance, Rescue Line and Rescue Maze challenges, where they have to build and program the robots themselves.
Below is video of a best of three rounds competition between a Lego Mindstorms NXT SumoBot and a Lego Mindstorms EV3 Sumobot:
SumoBot – A Lego Mindstorms Sumo Competition (Direct Link)
Note: The robots in the picture and video have both Ultrasonic and SumoEyes fitted, but only one sensor is actually used at a time. Which sensor is used is controlled by the SumoBot 6 Setup program.
The SumoEyes sensor from Mindstorms.com uses an infrared transmitter with two receivers so it can tell if the opponent is directly in front or to the left or right.
For more information or to purchase SumoEyes sensors, go to;
The archive file below contains the following:
- SumoBot 6.pdf – Instructions for building robots and using software
- Lego Mindstorms NXT SumBot 6.rbtx – Sumo program
- Lego Mindstorms NXT SumoBot 6 Setup.rbtx – Setup program
- Lego Mindstorms EV3 SumoBot6.ev3 – Sumo and Setup program
- SumoEyes.zip – NXT Block for SumoEyes
- Mindsensors-NXTSumoEyes.ev3b – EV3 Block for SumoEyes
Please download the file and read the instruction PDF file:
Please enjoy playing and learning with the SumoBot programs. Post your thoughts, feedback and comments below.
David
This article was originally posted on http://www.winthropdc.com/blog.
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