The Game and Strategy

The game is played on a game course split into two sides: red and blue. At the beginning of the match, the robots start in the starting zone and have 30 seconds of autonomous play to score double points. Then the 90-second manned-operation period starts and students try to score the more points than their opponent to win and move to the next round.

The game course is a X-Wing flying craft. Robots may play on both the ground level, or they can also ascend the elevator to access game play on the top level.

The several methods of scoring include:

• Spinning the X-Wing thrusters (weighted flywheel) as fast as you can (higher maximum RPM scores more points)

• Pulling the “Carbonite-frozen Han Solo” to a certain height

• Pushing stormtrooper figurines into a pit

• Placing stormtrooper figurines on a high ledge

• Tipping the lightsabers over to score a point multiplier

• Knocking over Darth Vader

Given that each match is only 2 minutes long, my strategy was to pick only one thing to do, and to do it extremely well. I chose to spin up the thrusters because it gives the most points and didn’t require taking the time to get up to the upper level of the game course. As I build the robot, I realized that I would have room to put another mechanism on the robot, so my strategy evolved to include a 4-bar linkage pusher that could help me tip the lightsaber to score up to a 3x point multiplier.

My three stage strategy proved to be an effective use of time. A simple autonomous maneuver helped me align to thruster. While I did not score double points in the autonomous period, this starting strategy left me the full 90 second left to score points.

My strategy helped me score a maximum of 146 points. In the end-of-semeter robotics competition, this was enough to land me a spot in the top 16 and a chance to compete in the finals.

The Robot

Flywheeler is built to prioritize the efficiency of the spinner wheel since that is key to scoring the most points. The spinner is mounted on a 2-axis suspension system which provides a spring-loaded normal force on the thruster, and additional compliance to absorb vibration. To get the robot to the thruster, a maneuverable but fast drive train was required to move the robot in position. The 4-bar-linkage pusher was added last as a “nice to have” in the event that I had enough time in a match to score the multiplier points.

I prototyped and tested one of the modular small spinners. I was so convinced that this was the correct architecture and I had designed in enough compliance and redundancy to ensure good contact with the thruster flywheel, however my prototype did not work. The small wheel barely moved the thruster.

I went back and looked at the math to see where I had gone wrong. If I assumed a no-slip condition, my spinner wheel and the thruster flywheel should act like gears. The problem was that I needed a bigger “gear”. I increased my spinner wheel to have the biggest diameter that could still fit within the robot size limits to create a 2:1 “gear” ratio.

However, with a bigger gear, the torque on the motor would increase. Then, the motors could not operate near no-load speed. I solved this by using multiple motors and gearing them up to increase both torque and no-load speed.