Playerstage

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Player/stage
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What is player stage

• System of programs designed to test robot control
  software
• Open source
• Compiles on X Windows computers (Linux, Mac OS x,
  etc)

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Why use player stage

• Robot availability
• Power requirements
• Initial debugging easier

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Components
Robot Control Software
Player
Stage
simple.cfg
simple.world
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Configuration files

• .cfg
• Defines the actual robot implementation
• Defines how player will interface with the robot
  implementation
• .world
• Used when testing in the simulator
• Defines the environment and initial placement of
  the robots

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Running the simulator

• Player program is in /usr/local/bin
• Example cfg and world files are in
  /usr/local/share/stage/worlds
• /usr/local/bin/player /usr/local/share/stage/wor
  lds/simple.cfg

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Controlling the robot

• Control programs interface to player via sockets
• Libraries are provided in C, C, and Java that
  manage the interface
• Programs contain mostly logic

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Program initialization

• parse_args
• Create instances of robot and its sensors
• PlayerClient robot(gHostname,gPort)
• Position2dProxy pp(robot,gIndex)
• LaserProxy lp(robot, gIndex)
• pp.SetMotorEnable(true)

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Control Loop

• try
• for ()
• robot.Read() //reads all robot data
• //do action
• pp.SetSpeed(.100,.5) //100 mm/sec and .5
  radians/sec
• catch (PlayerCcPlayerError e)
• //handle/print error

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Interfaces Position

• SetSpeed(velocity_mm_sec,angular
  velocity_rad_sec)
• robot_X_coord_metersGetXPos()
• robot_Y_coord_metersGetYPos()
• robot_Yaw_radGetYaw()
• isRobotStalled_boolGetStall()

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Interfaces Laser

• lp.GetCount()
• lpindex//get range reading
• Many more functions in documentations

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Interfaces Sonar

• Similar to laser
• Usually fewer so ranges are accessed by number
• sp.GetCount()
• spindex

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Homework
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Resources

• General documentation
• http//playerstage.sourceforge.net/index.php?srcd
  oc
• Tutorial
• http//playerstage.sourceforge.net/doc/Player-2.0.
  0/player/group__cplusplus__example.html
• Interface documentation
• http//playerstage.sourceforge.net/doc/Player-2.0.
  0/player/group__player__clientlib__cplusplus__prox
  ies.html
• Sample configuratiosn and world files
• /usr/local/share/stage/worlds