Robotic Actions

1
Robotic Actions

• Peter Watt
• BSc. Computing
• 3rd November 2002

2
Introduction

• The purpose of this presentation will be to look
  at how you can control the robot in order for it
  to carry out simple actions
• Go Forward, Turn Left, Open Gripper
• Actions can be linked, e.g. grasping an action
• Raise Gripper Open Gripper Close Gripper
  Lower Gripper
• Commands are controlled via a software interface
  such as ARIA or MIRO. For this presentation we
  will look at ARIA.

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Topics to be Covered

• This presentation will look at
• ARIA an overview
• Movement Commands using ARIA
• Examples of Code
• Gripper
• Use of this in my project
• Demonstration ?

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What is ARIA?

• What does it stand for?
• ActivMedia Robotics Interface for Application
• What is it?
• An API (Application Programming Interface)
• Usable under Win32, Linux
• Object orientated application
• Written in C
• Provides a robust client-side interface to a
  variety of robotic systems
• Included with every P-series robot
• Open Source (distributed under GNU license)

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ARIA cont.

• What does it do?
• Allows programmers to quick and easily develop
  and deploy code that offers close control over an
  ActivMedia Robot.
• Dynamically controls velocity, heading, relative
  heading, and other navigation settings
• Integrates user I/O bus, gripper, pan-tilt,
  bumpers, and other accessories
• Handles low-level client-server interactions
• Provides the foundation for higher level robotics
  applications such as Saphira
• Compatible with both Festival and Sphinx

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ARIA cont.

• Communicates via a client/server relationship.
• Uses either a serial connection (to talk to the
  robot) or a TCP/IP connection (to talk to a
  simulator
• Typically, developers use ARIA's high level
  controls in "actions" (behaviours) to read
  sensors and drive the robot

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Key Features of ARIA

• Dynamically controls velocity, heading, relative
  heading, etc.
• Integrates user I/O bus, gripper, pan-tilt,
  bumpers, and other accessories
• Polls all range devices with a single function
• Highly flexible
• Cross platform (Linux and Win32)
• Complete reference documentation
• Built-in threading system intended for
  multithreaded applications
• Built-in socket layer eases inter-program
  communication via network

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Key Features of ARIA

• Built-in actions for obstacle avoidance
• Eases implementation of custom actions
• Maintain sonar history and gain sonar readings in
  a region (box or polar)
• Utility code eases tasks such as built in time
  class, a class of math operations, and a position
  class, all with many built in  functions for
  doing common operations 
• Includes many examples illustrating ARIA features
  and applications
• Designed to be a solid base for large-scale
  applications
• High-quality professional code, designed before
  implementation

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Structure

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ArRobot class

• This class is the heart of ARIA
• Acts as a client-server communications gateway.
  It is the gathering point for many tasks such as
  actions or range-finding sensors.
• Most important class
• Examples of Methods
• void ArRobotsetVel (double velocity) - sets the
  velocity of the robot
• void move (double distance) - moves the distance
  indicated
• double getVel (void) - gets the translational
  velocity of robot

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ArAction class

• ArAction and ArActionDesired are used to create
  actions as opposed to direct control using
  ArRobot.
• ArAction is the base class used when defining an
  action.
• ArActionDesired should be used when you want to
  get the robot to carry out specific instructions
• class DriveTo public ArAction
• public DriveTo(ArGripper gripper)
• virtual DriveTo(void)
• virtual ArActionDesired fire(ArActionDesired
  currentDesired)
• virtual void setRobot(ArRobot robot)protected
• ArActionDesired myDesired double startup

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ArGripper class

• Used to control the gripper on the robot.
• Examples of Methods
• bool ArGripper gripOpen (void) - opens the
  gripper
• bool gripClose (void) - closes the gripper
• bool liftUp (void) - raises the gripper to the
  top
• bool liftDown (void) - lowers the gripper to the
  bottom

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Examples of Code

• include Aria.h
• class ActionGo public ArAction //class
  ActionGo is a subclass of ArAction
• ActionGo (double maxSpeed, double StopDistance)
  //constructor
• virtual ActionGo(void) //destructor
• //find out what the action wants
• virtual ArActionDesired fire(ArActionDesired
  currentDesired)
• //sets robot pointer
• virtual void setRobot(ArRobot robot)
• ArRangeDevice mySonar
• ArActionDesired myDesired
• double myMaxSpeed
• double myStopDistance

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Gripper close class

• class GripperClose public ArAction
• public
• GripperClose(ArGripper gripper)
• virtual GripperClose(void)
• virtual ArActionDesired fire(ArActionDesired
  currentDesired)
• virtual void setRobot(ArRobot robot)
• protected
• ArRangeDevice mySonar ArGripper myGripper
  ArActionDesired myDesired double gripper_state

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Gripper close methods

• GripperCloseGripperClose(ArGripper gripper)
  
• ArAction("GripperClose", "Got Object close
  gripper")
• mySonarNULL myGripper gripper
  gripper_state0
• void GripperClosesetRobot(ArRobot robot)
• myRobot robot mySonar myRobot-gtfindRangeD
  evice("sonar") if (mySonar NULL)
  deactivate()
• ArActionDesired GripperClosefire(ArActionDesire
  d currentDesired) myDesired.reset()
• if (mySonar NULL) deactivate()
  return NULL //Breakbeam in gripper activated
• if (myGripper-gtgetBreakBeamState() !0)
  //Close gripper
• myGripper-gtgripClose()
• //Stop robot myDesired.setVel(0)
• return myDesired

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Gripper an Overview

• Nose mounted 2-axis arm allows grippers to handle
  objects 1 to 21.5 cm wide
• 2 degree-of-freedom gripper provides sturdy, low
  maintenance handling
• Twin break beams between gripper paddles provide
  accurate positioning information
• Bump sensors inside each gripper provide allow
  software pressure controls
• Good response time of 3 seconds from fully open
  to fully closed position
• Strong 5.5 lbs. (2.5kg) lift capacity
• Vertical 4-in (9cm) rise allow object to be
  raised high or just above the floor to avoid
  blocking robot sonar
• Integrated in P2OS and Saphira software
• Compatible with Pioneer PTZ Camera Systems and
  other Pioneer accessories except for Front
  Bumpers.

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My Project

• How does this tie in with my project?

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Project

• Project is based on associating language terms
  with sensors in order for the robot to carry out
  the appropriate action when asked to
• Once program is complete for robots movements,
  will record readings from the robots sensors
  while it is carrying out these actions.
• Devise a representation of these actions in order
  that they can be linked with language terms

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Conclusion

• This has been a brief overview of how to use ARIA
  to get the robot to carry out simple actions
• If you want to learn more, there are manuals or
  you look at the websites below
• ARIA is available on the Linux machines on the
  Terraces
• For more info, look at
• http//www.activrobots.com and
• http//robots.activmedia.com

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Questions?