During my undergraduate experience I was a member of PUC-Rio's robotics team, Team RioBotz, that develops and build robots for international and national competitions. A video about the team can be found here. We participated in several national (Winter Challenge and Summer Challenge) and international competitions (RoboGames, Combots Cup and the All Japan Robot Sumo Tournament) with great success.
The team specialty is to build Combat Robots. As can be expected, such robots must be very robust to high impacts and also be able to withstand delivering such power. A few category I participated:
Middleweight Combat: Touro
Touro (Bull in Portuguese) is a very robust and compact 110lb (54kg) robot and was first designed in 2006. It kept evolving since then and it currently has a 1" thick 6061 T6 Aluminum waterjet cuted chassis that work as an ablative armor, absorbing the impact energy to protect the inner parts and electronics. It's weapon is a 35.3lb (16kg) 4340 steel drum tempered to 43 Rockwell C that have a "tooth" which hits the opponent, launching it up in the air. The weapon motor is a 4.5 HP AmpFlow A28-400 brushed motor that spins the drum up to 8000RPM. The C-shaped chassis optimized the geometry to withstand impacts and replaced the previous flat wall Al-Kevlar-Ti sandwich.
The SolidWorks model of Touro and it's rendering is showed below along with an exploded view of the robot:
You can check Touro in action during the RoboGames 2013:
Below, a few battle scars it collected.
Touro was Middleweight World Champion at the Combots Cup 2011, and also RoboGames 2007 and 2013!
Heavyweight Combat: Touro Maximus
Touro Maximus is the 220lb (100kg) version of Touro. It's the heaviest member of the Touro family of drumbots from RioBotz. Designed and built to debut at RoboGames 2009, it is the first and only heavyweight combot from Brazil.
After RoboGames 2011, it was completely redesigned and rebuilt. Its new chassis was waterjet cut from a 4.5" thick Aluminum plate. Both drum and wheel diameters were changed from 6" to 8" to increase weapon energy, drivetrain top speed and ground clearance.
The new tempered 4340 steel drum is a unibody with an integrated single tooth design. The drum's polygonal shape was created and optimized using Genetic Algorithms, which maximized the tooth "bite" while keeping its single tooth perfectly balanced without the need for counterweights. The odd spiral shape resulting from this evolutionary approach inspired the nickname "Snail drum."
You can check Touro Maximus in action during the RoboGames 2013
And at the StemTech 2014! Unfortunately the LiPo battery was squeezed inside the robot during the hit and this made it catch on fire. But no problem! Touro Maximus was reborn form the ashes for the next fight!
Some other pics of our big boy!
And finally Heavyweight World Champion at the StemTech Olympiad 2014!!!
And our humble tribute to the legend: Ziggy!
Below is the robot under gyroscope effect during test drive and it's SolidWorks model.
Drum Optimization Using Genetic Algorithms
The previous version of Touro Maximus weapon was a stainless steel cylinder with a 54 Rockwell C S7 tool steel tooth that used a tungsten alloy as counterweight. To optimize the new design I proposed a new solution using Genetic Algorithms to maximize the inertia and the tooth bite in a balanced drum.
Below is shown the proposed geometry. All the 13 radii composed a chromosome of an simulated population that would evolve to find the best individual, thus the optimized drum.
The drum was used by Touro for several competitons including the 2013 RoboGames championship!
The work was presented at the RoboGames 2012 Scientific Symposium:
Joao Luiz A. S. Ramos, and Marco A. Meggiolaro, “Drum Shape Design and Optimization using Genetic Algorithms”, Robogames Scientific Symposium, San Mateo, CA, 2012.
Our overwhelmed team after been awarded three gold medals at the VI Combots Cup.