Robotic Bulldozer Sumo

November 3rd, 2007, West Lafayette, Indiana, USA.

A group of five MINDSTORMS Community Partners (MCPs) gathered outside West Lafayette, Indiana to compete in the Sumo Challenge. The MCP group (self-named the Robotics Posse) consists of "Big" Bryan Bonahoom, John "The Builder" Brost, Brian "Cameraman" Davis, Steve "Sumo" Hassenplug, and Jay "The Kid" Kinzie.

Part One of the challenge was to take the LEGO Motorized Bulldozer (set #8275), add a LEGO NXT (set #8527), and battle them head-to-head in a sumo competition (where one robot tries to push another out of a circle). In order to interface the NXT to the Power Functions system in the bulldozer, we each used a HiTechnic NXT IRLink Sensor. This allows the NXT to send IR messages to the motors built into the bulldozer. Brian's program allowed him to switch between channels (1 to 4) while most others were simply hard-coded. I didn't notice anyone experiencing interference between bulldozers, but I'm sure there was some...

The Bulldozers: Each of the bulldozers were unique, and solidly represented the builder who brought it.

Bryan's dozer was able to detect opponents (and sometimes builders) using an ultra-sonic distance sensor and would slam a huge LEGO wheel down on them. When the weapon was activated, it would crash into the opposing dozer, sending pieces flying and sometimes snapping the opponent's treads. The dozer's weakness was it's slow searching speed.

Brian's dozer was a classic sumo robot. It was very solid and was able to detect the edge of the ring, and stay in, using a light sensor that was well hidden behind the front grill. While most others were trying to detect opponents, this one simply tried to keep moving, and stay in the ring. It's weakness was it's inability to detect the opponent.

John's dozer had a beautifully created rear attachment. It would snap on, in place of the standard rear attachment, and looked as if it was designed to be part of the original kit. The attachment was a spinning wheel, which looked like it could tear through both the opponent, and the sumo ring. The weakness was that it used the stock drive train for the rear assembly, so it had very actual little power.

Steve's dozer was nothing more than the stock dozer, with an NXT hanging on the back, and two ultrasonic sensors on the front. The programming was done the morning of the event, and once the program was tweaked, it worked very well. The weakness was the fact that the ultrasonic sensor threshold was too high for the first part of the event, so it was detecting objects outside the sumo ring, and trying to attack them.

Jay's robot was not exactly the stock dozer. It appeared he did use several of the pieces from the bulldozer set, but the robot bared little resemblance to the actual bulldozer. While it did look kind of cool, in the end it's weakness was a total lack of programming.

The Video

There were many battles during the day, but no score. The final results can be seen on the video. Some of the highlights of the event include: Bryan's huge wheel breaking a track on Brian's dozer. John's spinning wheel of death. Brian's dozer just driving around the ring, staying in the circle for several minutes (like it should).

The different categories that could have been awarded (to bulldozers, not builders) were:

Best Looking: John
Most Destructive: Bryan
Most Reliable: Brian
Most Stock: Steve
Most Stationary: Jay