REU 2007-Kicker Design for Soccer Playing Robots Jameson Beebe, Mentors: Dr. Alfredo Weitzenfeld L1 D1 1 Introduction The USF Robobulls are a group of engineering students at USF who participate in the design of soccer playing robots. This is done with the intent to compete at the robotics soccer competition Robocup in the small sized league. 2 Results The actual results differed from the results achieved in the simulations. In the lab tests, the capacitor only charged to approximately 170V in 30 seconds while the simulation predicted that the capacitor would charge to 250V in 3.79 seconds. The reasons behind this difference was in the size of the inductor used and the frequency at which the circuit was pulsed. The mosfet used in the lab test was heating up too much and a few mosfets were burned up because of the heat. V2 M1 IRF 740 C1 V1 To resolve this, a smaller inductor needs to be used, and the circuit needs to be pulsed at a much higher frequency (maybe in the 1.5Mhz range). This will allow less current to be pulled through the mosfet for a shorter time and reduce the heat imposed on the mosfet. 0 Kicker Circuit schematic 300 (3.7967,250.571) Robots used in the small size league competition. Conclusion 200 Objective The robots need to kick a ball as a fundamental part of the game. The current kicker being used is a DC-DC charger and is expensive, slow, and heavy. As a primary objective, I had to redesign the kicker circuit to be cheaper, faster, and lighter. The robots need to be able to kick the ball approximately 20 feet. Methodology For a higher voltage to be achieved, I decided to use a boost converter design as shown below. The actual setup was tested using two circuits in parallel to charge two different capacitors. When the capacitors were fully charged, they both simultaneously discharged through the solenoid and produce a very strong kick. 100 (3.8000,35.782) 0 0s V(U4:2) 0.5s -I(R3) 1.0s 1.5s 2.0s 2.5s 3.0s 3.5s Time When two charging circuits were used in parallel, this simulated result was achieved. 4.0s This circuit is a very good design for use in not only a robotic kicking circuit, but in many other high voltage applications too. Also, it was found out that using the boost converter design, it doesn’t matter how high of current you draw, it is the physical amount of current you draw. So you can use a small amount of current, but pulse the circuit really fast and achieve the same results if not better. The main limiting factor in this research was waiting for parts to arrive at the lab. At times, it would take 2 weeks for new parts to arrive, and fully test. Acknowledgements I would like to thank our mentor Alfredo Weitzenfeld, and all those who supported USF Robobulls by monetary contribution. Department of Computer Science & Engineering