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
Team Lucky Star, 2004Weber, 2004
University of Auckland, 2005
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
Required Torque: 43 mN.m
Maximum Speed: 1.4 m/s
MGEN, 2005
Mechanical Design• Kicker Device
• Spring Powered
• Pneumatics
• Solenoid
Weber, 2004
Mechanical Design• Kicker Device
Final Design: Pull-typesolenoid 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 from3 mm aluminium
• Modular design toaid in modificationof subsystems
Mattner, 2005
Vision System
Fire Wire Camera (15 FPS)
Frame
Vision Software
The Imaging Source, 2005 Mattner, 2005
• Equipment
Vision SystemColour Identification System
Pink = Centroid r1
Purple = Direction r1
Yellow = Centroid r2
Blue = Direction r2
Orange = Ball
Vision SystemObject 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 operation1. Ball not in possession
2. 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
CommunicationsSystem• 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
CommunicationsSystem• Byte 7: Solenoid Instructions
Set to 1 for energised, 0 for de-energised
• Byte 8: ChecksumSum 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
AcknowledgementsWe 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???