2005 Level IV Design Project SOCCER ROBOTS Michael Hill Nicholas Jones Michael Shanahan Supervisor: Dr Frank Wörnle.

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???