An Introduction to RoboCup

1
An Introduction to RoboCup

• October 26, 2006
• by Michael Floyd
• Portions by Kevin Lam and Paul Marlow

2
Agenda

• Overview of RoboCup
• How Games Are Played
• Demonstration Game
• Client/Server Communication
• Existing Clients and Tools

3
Overview of RoboCup

• The Robot World Cup Initiative
• By the year 2050, develop a team of fully
  autonomous humanoid robots that can win against
  the human world soccer champion team.
• A standard problem for AI research

4
Overview of RoboCup

• Started in 1992 as the Robot J-League (Japan)
• First games and conferences in 1997
• Workshops, conferences and yearly competitions

5
RoboCup Leagues
6
RoboCup Simulator

• Server (2-D and new 3-D)
• Monitor clients
• Player clients (i.e. agents!)
• Coach clients

7
Clients and Server

• One server
• Up to 11 clients per team (plus coach)
• Clients/server communicate via UDP/IP

8

• Can be written in any language (C, Java,
  Smalltalk, ...)
• Can be run on same machine or a network
• Clients may talk only to the server... not to
  each other!

9

• Monitor(s) used to visualize the action and/or
  interrupt the game
• Coaches (optional) to give guidance to teams

10
RoboCup Clients

• Autonomous agents
• The brains of the players
• Sensory information received from server,
  decision made, action command sent back to server
• One agent represents one player
• One agent can designate itself as the goalie

11
RoboCup Clients
12
RoboCup Server

• Keeps time (typically 6000 (10 mins) simulator
  cycles, 10 cycles per second)
• Receives client messages, updates world model,
  sends back new status information
• Automated Referee tracks current play mode

13
Play Modes
14
Starting a Game

• Download and install applications
• Run the Server (default host is localhost and
  default port is 6000)
• Run the Monitor, connecting to the host and port
  of the Server
• Connect the players to the Server host and port
• Start the kick-off!

15
Demonstration
16
Connection Protocols

• From client to server
• Initiate a connection
• Reconnect
• Quit
• From server to client
• Confirms the connection and provides the
  players uniform number, side of field, and
  current state of the game

17
An Example

• Player Connects and joins MyTeam (init
  MyTeam)
• Server Tells the player they are connected,
  have uniform 1, are on the right side of the
  field, and the game is pre-kickoff (init r 1
  before_kick_off)
• Server Tells player current location and
  location of visible objects (see 0 ((goal r) 66.7
  33))

18
Client Commands
19
Client Sensor Protocol

• Three main message types
• Hear
• See
• Sense_Body
• Noise models for each

20
Hear Messages

• Can hear one message per team per cycle
• (hear Time Sender Message)
• Sender online_coach_left/right, referee, self,
  Direction
• Direction -180 180 degrees

21
See Messages

• (see Time ObjInfo)
• ObjInfo
• (ObjName Distance Direction DistChange DirChange
  BodyFacingDir HeadFacingDir) or
• (ObjName Distance Direction DistChange DirChange)
  or
• (ObjName Distance Direction) or
• (ObjName Direction)

22
Flags and Lines
23
See Example

• (see 18 ((f r t) 44.7 -22) ((f g r b) 47.9 30)
  ((f g r t) 42.5 13) ((f p r c) 30.3 34 -0 0) ((f
  p r t) 25.3 -7 0 0) ((f t r 40) 36.2 -37) ((f t r
  50) 44.7 -29) ((f r 0) 49.4 20) ((f r t 10) 47 8)
  ((f r t 20) 46.5 -3) ((f r t 30) 48.4 -15) ((f r
  b 10) 53.5 30) ((f r b 20) 59.1 38) ((f r t) 44.7
  -22) ((f g r b) 47.9 30) ((g r) 44.7 22) ((f g r
  t) 42.5 13) ((f p r c) 30.3 34) ((f p r t) 25.3
  -7 0 0) ((f t r 40) 36.2 -37) ((f t r 50) 44.7
  -29) ((f r 0) 49.4 20) ((f r t 10) 47 8) ((f r t
  20) 46.5 -3) ((f r t 30) 48.4 -15) ((f r b 10)
  53.5 30) ((f r b 20) 59.1 38) ((p ExampleTeam")
  36.6 28) ((l r) 41.7 -89))

24
Sense_Body Messages

• (sense_body Time
• (view_mode high low narrow normal
  wide)
• (stamina StaminaEffort)
• (speed AmountOfSpeed DirectionOfSpeed)
• (head_angle HeadAngle)
• (kick KickCount)
• (dash DashCount)
• (turn TurnCount)
• (say SayCount)
• (turn_neck TurnNeckCount)
• (catch CatchCount)
• (move MoveCount)
• (change_view ChangeViewCount))

25
Sense_Body Example

• (sense_body 19 (view_mode high normal) (stamina
  4000 1) (speed 0 0) (head_angle 0) (kick 0) (dash
  0) (turn 0) (say 98) (turn_neck 0))

26
Coaches

• Privileged clients used to provide assistance
• Receives noise-free view of the whole field
• Can only send occasional messages to players
  (info, advice, freeform, etc.)
• Used for opponent modelling, game analysis,
  giving strategic tips to teammates

27
The Environment

• accessible vs inaccessible Only sees what is in
  front of it (with noise)
• deterministic vs non-deterministic Just because
  agent wants to kick ball doesnt mean it will
  happen
• static vs dynamic The players and ball will
  constantly be moving
• discrete vs continuous Player can take any
  position on the field

28
Some RoboCup Clients

• UvA Trilearn (Amsterdam) (2003 champion)
• CMUnited (Carnegie Mellon)
• Everest (China)
• FC Portugal 2003 (Portugal)
• HELIOS (Japan)
• Magma Furtwangen (Germany)

29
Typical Approaches

• Hard-coded behaviour
• Scripted behaviour (e.g. planning)
• Neural Networks
• Opponent Modelling
• Layered Learning
• Behaviour Networks

30
Example a4ty

• Layered skills hierarchy (pass, intercept)
• Follow advice of coach
• Competed in RoboCup competitions

31
Example Krislet

• Only one strategy run to the ball and try to
  kick it!
• Surprisingly effective can beat many more
  complex teams
• Written in Java, easy to extend

32
Example RoboPlayer

• Based off of Krislet
• Allows Krislet-type players to have states
  (forward, defense, goalie)

33
Example STRIPSlet

• Based off of Krislet
• Uses STRIPS-style linear planning
• Works at achieve a set of goals
• The base-version only has one goal putting the
  ball in the net

34
Developing Clients

• www.robocup.org
• Soccer Server Manual
• Start with Krislet, RoboPlayer or Stripslet
• Soccer Server 9.1.5

35
Carleton Projects

• Tool to log client-server communications
  (LogServer)
• Imitative Agent (RCScenes)
• Human-user interface (In The Agents Shoes)

36
References

• Most of the information about RoboCup itself was
  taken using from the RoboCup Soccer Server
  manual.
• For the latest manuals and code, visit the
  RoboCup project website at
• http//sourceforge.net/projects/sserver

37
Support

• Project links and executables are available from
  http//chat.carleton.ca/mfloyd/robocup/
• Feel free to e-mail me with any questions
  mfloyd_at_connect.carleton.ca