buzz_argos

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ARGoS is a fast multi-robot simulator that can interoperate with Buzz.

To install ARGoS, go to http://www.argos-sim.info/core.php and install a binary package. To get started with ARGoS, refer to the examples.

Compile and install Buzz following the instructions reported in the GitHub page. Make sure to compile Buzz after having installed ARGoS, so the compilation scripts will also compile the ARGoS integration code.

The Buzz integration library for ARGoS is composed of two elements:

  1. A set of ARGoS controllers. At the moment, available controllers include one for the foot-bot, one for the Khepera IV robot (both wheeled robots), and one for the Spiri (a commercial quad-rotor). More can be added easily by subclassing CBuzzController, defined in $PREFIX/include/buzz/argos/buzz_controller.h. $PREFIX depends on your system and is usually /usr or /usr/local.
  1. A special definition of ARGoS' QtOpenGL user functions, which allow Buzz scripts to draw in the OpenGL visualization of ARGoS. With these, a developer can write debugging information on top of each robot.

To have ARGoS find the Buzz integration library in case you installed it in a non-default location, set the environment variable ARGOS_PLUGIN_PATH. This variable is a :-separated list of directories in which ARGoS looks for libraries before launching an experiment. For instance:

$ export ARGOS_PLUGIN_PATH=/opt/lib/buzz

If you installed Buzz without specifying a custom installation prefix (e.g., using only cmake -DCMAKE_BUILD_TYPE=Release ../src; make; make install), you don't need to set ARGOS_PLUGIN_PATH.

Defining an ARGoS experiment file

To use ARGoS and Buzz together, define your .argos experiment file as usual.

However, instead of a custom controller, in the <controllers> section use <buzz_controller_footbot> or <buzz_controller_spiri> (or both!), depending on the robots you intend to use. For example, if you want to use both controllers, write something similar to this:

<controllers>
 
  <!-- Include this if you're using foot-bots -->
  <buzz_controller_footbot id="bcf">
    <actuators>
      <differential_steering implementation="default" />
      <leds                  implementation="default" medium="leds" />
      <range_and_bearing implementation="default" />
    </actuators>
    <sensors>
      <range_and_bearing implementation="medium" medium="rab" show_rays="true" noise_std_dev="0" />
    </sensors>
    <params />
  </buzz_controller_footbot>
 
  <!-- Include this if you're using Khepera IV -->
  <buzz_controller_kheperaiv id="bckiv">
    <actuators>
      <differential_steering implementation="default" />
      <leds                  implementation="default" medium="leds" />
      <range_and_bearing implementation="default" />
    </actuators>
    <sensors>
      <range_and_bearing implementation="medium" medium="rab" show_rays="true" noise_std_dev="0" />
    </sensors>
    <params />
  </buzz_controller_kheperaiv>
 
  <!-- Include this if you're using Spiri -->
  <buzz_controller_spiri id="bcs">
    <actuators>
      <quadrotor_position implementation="default" />
      <range_and_bearing  implementation="default" />
    </actuators>
    <sensors>
      <range_and_bearing implementation="medium" medium="rab" show_rays="false" />
      <positioning       implementation="default" />
    </sensors>
    <params />
  </buzz_controller_spiri>
 
</controllers>
 
...
 
<arena ...>
 
   <!-- Place a foot-bot in the arena -->
   <foot-bot id="fb0" rab_data_size="100">
      ...
      <controller config="bcf" />
   </foot-bot>
 
   <!-- Place a Khepera IV in the arena -->
   <kheperaiv id="fb0" rab_data_size="100">
      ...
      <controller config="bcf" />
   </kheperaiv>
 
   <!-- Place a Spiri in the arena -->
   <spiri id="fb0" rab_data_size="100">
      ...
      <controller config="bcs" />
   </spiri>
</arena>

To activate drawing, use buzz_qt to indicate that you want to use the Buzz QtOpenGL user functions:

<visualization>
  <qt-opengl>
    <user_functions label="buzz_qt" />
  </qt-opengl>
</visualization>

You can launch ARGoS as usual, with the command:

$ argos3 -c myexperiment.argos

Make sure the parameters arena/<robot>/rab_msg_size are set to relatively large values, such as 100 bytes as reported in the above examples.

Inspecting a Robot's State

To understand what's happening on a specific robot, shift-click on it in the ARGoS visualization to select it. This opens a tree widget in the Buzz editor that reports the value of all the variables, and the list of available functions on the robot.

Debugging Information

The Buzz integration library offers a data structure, called debug, that allows the developer to perform several operations.

Writing Text on Top of a Robot
Drawing the Trajectory of a Robot

You can draw the trajectory of the robot as it moves.

  • debug.trajectory.enable(maxpoints,r,g,b)
    • enable trajectory tracking setting how many points should be stored and the drawing color
  • debug.trajectory.enable(maxpoints)
    • enable trajectory tracking setting how many points should be stored
  • debug.trajectory.enable(r,g,b)
    • enable trajectory tracking keeping maxpoints' last value and setting the drawing color
  • debug.trajectory.enable()
    • enable trajectory tracking keeping maxpoints' last value (default is 30)
  • debug.trajectory.disable()
    • disable trajectory tracking
  • debug.trajectory.clear()
    • delete all the trajectory points
Drawing Vectors
  • debug.rays.add(r,g,b, x,y,z)
    • draw a ray from the reference point of the robot to (x,y,z).
    • (x,y,z) is expressed wrt the robot reference frame
  • debug.rays.add(r,g,b, x0,y0,z0, x1,y1,z1)
    • draw a ray from (x0,y0,z0) to (x1,y1,z1)
    • (x0,y0,z0) and (x1,y1,z1) are expressed wrt the robot reference frame
  • buzz_argos.1521415191.txt.gz
  • Last modified: 2018/03/18 23:19
  • by root