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2005 Level IV Design Project SOCCER ROBOTS Michael Hill Nicholas Jones Michael Shanahan Supervisor: Dr Frank Wörnle RoboCup • International robotic soccer competition • Promotes studies in: • • • Automation Artificial Intelligence Strategic Programming Goals & Objectives • Research & develop a design meeting RoboCup small-size league entry criteria • Manufacturing a team of three such robots • Development & implement a vision system to enable multi-agent coordination Goals & Objectives • Design & implement a communications system to facilitate automation & strategic game-play • Comply with the AU$250.00 budget • Provide a solid foundation for future project teams to build upon & achieve success Design Overview • • • • • • Mechanical Design Vision System AI Software Communications System Current & Future Work Conclusion Mechanical Design • Drive System • Kicker Device • Power • Chassis Mechanical Design • Drive System • Two Wheel Differential • Omnidirectional University of Auckland, 2005 Weber, 2004 Team Lucky Star, 2004 Mechanical Design • Drive System Final Design: A differential drive system using M42SP-5 stepper motors. • • • Cost effective Readily available Satisfy torque and speed requirements Mechanical Design • Drive System – Motor Selection Performance Specifications • Acceleration 1 m/s2 • Velocity 1 m/s Parameters • Robot Mass: 1.9 kg • Wheel Radius: 30 mm • Step Size: 7.5o • Motor Speed: 365 pps MGEN, 2005 Required Torque: 43 mN.m Maximum Speed: 1.4 m/s Mechanical Design • Kicker Device • Spring Powered • Pneumatics • Solenoid Weber, 2004 Mechanical Design • Kicker Device Final Design: Pull-type solenoid with lever • Cost effective • Simple to build Mechanical Design • Power Powered Devices: • MiniDragon+ development board (5V) • Stepper Motors and Drivers (12V) • Solenoid (12V) • RF Receiver (5V) Power Source: • Ten 1.2V rechargeable AA batteries in series Mechanical Design • • Chassis Constructed from 3 mm aluminium Mattner, 2005 • Modular design to aid in modification of subsystems Vision System • Equipment Fire Wire Camera (15 FPS) Frame Vision Software The Imaging Source, 2005 Mattner, 2005 Vision System Colour Identification System Pink = Centroid r1 Purple = Direction r1 Yellow = Centroid r2 Blue = Direction r2 Orange = Ball Vision System Object Tracking Vision System Takes an image Returns it to the vision software Locates the positions Returns them to the AI System AI Software • Controls all robotic movement & kicking • MATLAB code & Simulink block diagrams converted to C-code • Two phases of operation 1. 2. Ball not in possession Ball in possession AI Software • Ball Not In Possession Assumes rate of acceleration is constant over small sample time Loop performed every five samples AI Software • Ball in possession Constant maxKick defines furthest the ball can be projected by kicker device Ball is kicked once dist2Goal is less than maxKick Similar algorithm for passing AI Software • Problem: Data reception too slow for effective closed loop navigation • Solution: AI provides several instructions per iteration • Development of game-play strategy limited due to lack of opposition Communications System • Robot instructions are sent in 8-byte telegrams via radio transceivers • Signals are broadcast to all three robots on same frequency • Data Transfer Rate = 12.5 instructions per second Communications System • Bytes 1-4: Telegram Information Contains information about the telegram itself, including target robot • Bytes 5 & 6: Motor Instructions Signed Integer varying between -127 to +127 representing speed and direction for the left and right motors, respectively Communications System • Byte 7: Solenoid Instructions Set to 1 for energised, 0 for de-energised • Byte 8: Checksum Sum of transmitted bits, which must be equal to the sum of received bits Current Work • Successful in achieving: • Effective & cost efficient design • Vision System provides object tracking • AI Software with predictive motion nearing completion • Communications system allows remote interaction Future Work • Group Aims: • Functional team of three robots • Perform standard soccer actions e.g. pass, shoot & dribble • Ball trajectory prediction software • Communications system supports continuous robot coordination Future Work • Recommended Development: • Manufacture opposition team & develop defensive AI software • Improve vision system data rates to facilitate faster game-play • Incorporate strategic game-play Conclusion • Project budget was the most defining constraint • Goals set were inherently optimistic • Were able to achieve majority of all fundamental hopes for project Acknowledgements We would like to thank the following people Dr Frank Wörnle, our supervisor Bill, Richard and Steve from the mechanical workshop Silvio and Derek from the electronics workshop Carnegie Mellon University for the vision drivers Yasutake and Taiki from the 2005 Osaka University Team Questions???