Bathymetry Integration

Contents

• Overview
• Tutorial: How-to
  • Quickstart
  • Bathymetry Plugin settings
  • Initial positioning of the vehicle
  • GPS Viewer
• For more bathymetry tiles

Overview

A bathymetry integration plugin that automatically spawns and removes bathymetry DEM grids converted preliminarily from high-resolution NOAA bathymetry data.

• Features
  • Automatic spawn/remove with vehicle locations
  • Overlaps for mission continuity
  • Relocate the vehicle to the designated initial latitude and longitude at the start
  • Use bathymetry tile dissected with depth-dependent texture
  • GPS Viewer to see vehicle's whereabouts

The plugin is defined at .world file and would require input settings used for preliminarily converted bathymetry data (prefix, spacings, number of columns/rows, anchored latitude/longitude). The bathymetry tile data is located at dave/models/dave_bathymetry_models/.Also, each robot will provide its locations with intervals defined at urdf. The plugin is also usable for multiple robots.

Tutorial: How-to

Quickstart

0. This quickstart assumes you have finished the installation of dave. The bathymetry plugin uses latitude and longitude coordinates to recognize which tiles to spawn and remove. To do so, it uses the GDAL library to convert in between UTM(epsg:4326; X/Y coordinates) coordinate system used in the simulation and WGS86(eps:3857, Latitude/Longitude) coordinates system.

   # For initial lat/lon spawning
   sudo apt-get install python3-gdal
   # For GPS Viewer
   sudo apt-get install libxtst6
   # Install required python3 modules
   pip3 install folium PyQtWebEngine pyqt5-tools

1. Download files for bathymetry demo and recompile to install

   downloading a file from google drive became complicated. Use the long line command below. Or, use this link

   # Install wget
   sudo apt-get install wget 
   # Download demo files archive
   wget --load-cookies /tmp/cookies.txt "https://docs.google.com/uc?export=download&confirm=$(wget --quiet --save-cookies /tmp/cookies.txt --keep-session-cookies --no-check-certificate 'https://docs.google.com/uc?export=download&id=1lOqG5cdf5NEHnxsqKyEWNgQ0Ugk6u80A' -O- | sed -rn 's/.*confirm=([0-9A-Za-z_]+).*/\1\n/p')&id=1lOqG5cdf5NEHnxsqKyEWNgQ0Ugk6u80A" -O Dave_Bathymetry_Demo.tar.gz && rm -rf /tmp/cookies.txt

   Then, move the file to appropriate location and extract

   # Move downloaded file to dave directory
   mv Dave_Bathymetry_Demo.tar.gz ~/uuv_ws/src/dave
   cd ~/uuv_ws/src/dave
   # Extract the demo files
   tar -xzvf Dave_Bathymetry_Demo.tar.gz
   # recompile
   cd ~/uuv_ws
   catkin build

2. Run gazebo with roslaunch command for bathy_dave launch file:

   roslaunch dave_demo_launch dave_bathymetry_demo.launch

3. Unpause the gazebo by clicking the play button at the bottom-left of the window

4. As the clock ticks in the ROS Server, set_init_latlon will reposition the vehicle to the initial position defined at the launch file

5. Zoom out (scroll down) to see the edge of the loaded bathymetry grid tile and the Rexrov

6. Run this command on a new terminal window Assume that you are in the dave directory

   python3 ~/uuv_ws/src/dave/gazebo/dave_gazebo_bathymetry_misc/merry_go_round.py

The merry_go_round.py script will move the vehicle in a circle. You may change the script parameter inside to modify center lat/lon, radius, depth, angular speed.

Bathymetry Plugin settings

The details of the plugin settings are described at the end of the dave_bathymetry_demo.world file

    <plugin name="bathy_dave_plugin" filename="libdave_bathymetry_world_plugin.so">
      <bathymetry interval_s="0.1">
        <grid prefix="MontereyBay" tiles_to_keep="1" priority="1" colmax="10" rowmax="10"
              anchor_lon="-70.699" anchor_lat="41.509" spacing_lon="0.012" spacing_lat="0.010" />
      </bathymetry>

Also, the update rate for the tiles is specified in each robot description. dave/urdf/robots/rexrov_description/urdf/rexrov_oberon7_bathymetry.xacro

  <gazebo>
      <plugin name="gazebo_ros_control" filename="libgazebo_ros_control.so">
        <robotNamespace>/$(arg namespace)</robotNamespace>
        <robotParam>/$(arg namespace)/robot_description</robotParam>

        <bathymetry>
          <interval_s>0.1</interval_s>
        </bathymetry>

      </plugin>
  </gazebo>

Initial positioning of the vehicle

At dave/examples/dave_demo_launch/launch/dave_bathymetry_demo.launch

<arg name="bathymetry_prefix" value="MontereyBay"/>
<arg name="robot_name" value="rexrov"/>
<arg name="initial_latitude" value="36.805"/>
<arg name="initial_longitude" value="-121.810"/>
<arg name="initial_depth" value="-5"/>
...
...
<!-- Set initial position using latitude and longitude (EPSG:4326) -->
<include file="$(find set_init_latlon)/launch/set_init_latlon.launch">
    <arg name="namespace" value="$(arg robot_name)"/>
    <arg name="init_lat" value="$(arg initial_latitude)"/>
    <arg name="init_lon" value="$(arg initial_longitude)"/>
    <arg name="depth" value="$(arg initial_depth)"/>
</include>

• robot_name : name of the vehicle model
• initial_latitude : initial latitude [deg]
• initial_longitude : initial longitude [deg]
• initial_depth : initial depth [m]

GPS Viewer

<!-- GPS Viewer -->
<include file="$(find gps_map_viewer)/launch/gps_map_viewer.launch">
    <arg name="namespace" value="$(arg robot_name)"/>
    <arg name="refresh_rate" value="1.0"/>
    <arg name="save_html" value="True"/>
</include>

• namespace : name of the vehicle model
• refresh_rate : refresh rate for GPS position marker update in the map
• save_html : Save GPS log as seen on the viewer as HTML which will be saved at /tmp/GPSViewer_log.html which you can open with a browser
• default_zoom : set initial zoom (range from 0 to 15, larger mean more zoom)

Importing more bathymetry data

• The bathymetry data need to be converted to be imported using the plugin. The converter to obtain bathymetry tiles from RAW bathymetry files can be found at Bathymetry converter.

*The plugin was developed by Micahel Jakuba at WHOI and modified and implemented to the dave project by Woensug Choi.