Notes

• Platform versions: ROS Melodic, Ubuntu 18, Gazebo 9
• Bosch UUV Simulator, https://roscon.ros.org/2018/presentations/ROSCon2018_uuvsimulator.pdf
  • plume tracking
  • Gazebo plugins and ROS modules

Working with uuv_simulator

• If installed from package for ros-kinetic, roslaunch --files uuv_descriptions upload_rexrov.launch shows:

  /opt/ros/melodic/share/uuv_assistants/launch/message_to_tf.launch
  /opt/ros/melodic/share/uuv_descriptions/launch/upload_rexrov_default.launch
  /opt/ros/melodic/share/uuv_descriptions/launch/upload_rexrov.launch
  

  Rather than installing and using this package, build it from source under workspace uuv_ws.

• When installed from our uuv_ws workspace, roslaunch --files uuv_descriptions upload_rexrov.launch shows:

  /home/bdallen/uuv_ws/src/uuv_simulator/uuv_descriptions/launch/upload_rexrov.launch
  /home/bdallen/uuv_ws/src/uuv_simulator/uuv_descriptions/launch/upload_rexrov_default.launch
  /home/bdallen/uuv_ws/src/uuv_simulator/uuv_assistants/launch/message_to_tf.launch
  

  and roslaunch --files uuv_gazebo_worlds ocean_waves.launch shows:

  /opt/ros/melodic/share/gazebo_ros/launch/empty_world.launch
  /home/bdallen/uuv_ws/src/uuv_simulator/uuv_gazebo_worlds/launch/ocean_waves.launch
  /home/bdallen/uuv_ws/src/uuv_simulator/uuv_assistants/launch/publish_world_ned_frame.launch
  

Exploring uuv_simulator

In page uuv_simulator reference we launched the ocean waves world and spawned a UUV at coordinate(0,0,-20). Here we examine the .launch files, .world files, and other code that makes this happen. Later we explore additions to this to provide a target capability: Grasp a ceramic cup.

ocean_waves.launch

Launch file ocean_waves.launch does this:

• Include Gazebo's empty_world.launch.
• Include uuv_assistants file publish_world_ned_frame.launch.
• Start node publish_world_models running publish_world_models.py.
• Optionally launch uuv_assistants file set_simulation_timer.launch.

upload_rexrov.launch

On default, starts upload_rexrov_default.launch with initial x,y,z,roll,pitch,yaw values.

empty_world.launch

This launch file, https://github.com/ros-simulation/gazebo_ros_pkgs/blob/jade-devel/gazebo_ros/launch/empty_world.launch, starts Gazebo, defining default parameters and opening /usr/share/gazebo-9/empty.world:

<?xml version="1.0" ?>
<sdf version="1.5">
  <world name="default">
    <!-- A global light source -->
    <include>
      <uri>model://sun</uri>
    </include>
    <!-- A ground plane -->
    <include>
      <uri>model://ground_plane</uri>
    </include>
  </world>
</sdf>

which defines world "default" with light and ground.

ocean_waves.launch

For launch file syntax, see http://wiki.ros.org/roslaunch.

Sensors

File ~/uuv_ws/src/uuv_simulator/uuv_assistants/templates/robot_model/urdf/sensors.xacro.template identifies example sensors: GPS, Pose 3D sensor, forward-looking sonar, DVL, RPT, Pressure, IMU, camera. See ~/uuv_ws/src/uuv_simulator/uuv_sensor_plugins/uuv_sensor_ros_plugins/urdf/*.xacro for more.

File ~/uuv_ws/src/uuv_simulator/uuv_descriptions/robots/rexrov_sonar.xacro has xacro:forward_multibeam_sonar_m450_130. It uses plugin name uuv_plugin filename libuuv_underwater_object_ros_plugin.so built from ~/uuv_ws/src/uuv_simulator/uuv_gazebo_plugins/uuv_gazebo_ros_plugins/src/UnderwaterObjectROSPlugin.cc. It connects services for modeling underwater properties.

File ~/uuv_ws/src/uuv_simulator/uuv_sensor_plugins has plugins, for example ~/uuv_ws/src/uuv_simulator/uuv_sensor_plugins/uuv_sensor_ros_plugins/include/uuv_sensor_ros_plugins/gazebo_ros_image_sonar.hh, .cpp. From CMakeLists.txt this makes image_sonar_ros_plugin.so. File image_sonar_ros_plugin.so is referenced in ~/uuv_ws/src/uuv_simulator/uuv_sensor_plugins/uuv_sensor_ros_plugins/urdf/sonar_snippets.xacro. File sonar_snippets.xacro is referenced in ~/uuv_ws/src/uuv_simulator/uuv_sensor_plugins/uuv_sensor_ros_plugins/urdf/sensor_snippets.xacro. File sensor_snippets.xacro is included from the following:

• ~/uuv_ws/src/uuv_simulator/uuv_assistants/templates/robot_model/urdf/base.xacro.template
• ~/uuv_ws/src/uuv_simulator/uuv_descriptions/urdf/rexrov_base.xacro
• ~/uuv_ws/src/uuv_simulator/uuv_sensor_plugins/uuv_sensor_ros_plugins/urdf/sensor_snippets.xacro
• ~/uuv_ws/src/uuv_simulator/uuv_tutorials/uuv_tutorial_rov_model/urdf/rov_example_base.xacro

File rexrov_base.xacro is included in several rexrov_* files, including ~/uuv_ws/src/uuv_simulator/uuv_descriptions/robots/rexrov_oberon7.xacro, which is included in the ~/uuv_ws/src/uuv_simulator/uuv_descriptions/launch/upload_rexrov_oberon7.launch file which we are using, meaning that the image_sonar_ros_plugin plugin is available in Gazebo.