Bathymetry Integration

Contents

• Overview
• Tutorial: How-to
  • Quickstart
  • Plugin settings
• 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. 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
# Install required python3 modules
pip3 install google-api-python-client earthengine-api pyCrypto
pip3 install earthengine-api --upgrade
pip3 install folium

# Authenticate google earth engine
earthengine authenticate
# It will give you a link where you can log in. This happens only once

1. Download files for bathymetry demo and recompile to install

# downloading a file from google drive became compliated. Install and use gdown. Or, use [this link](https://drive.google.com/file/d/1lOqG5cdf5NEHnxsqKyEWNgQ0Ugk6u80A/view?usp=sharing)
# Install gdown
pip install gdown 
# Download demo files archive
gdown --id 1lOqG5cdf5NEHnxsqKyEWNgQ0Ugk6u80A
# 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_make

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 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 rendered data as HTML which will be saved at /tmp/GPSViewer_log.html
- `default_zoom` : set initial zoom (range from 0 to 15, larger mean more zoom)
- `meadianColorDepth` : The bathymetry tile is divided into two layers for coloring: shore and deepsea. This decies which depth to divide.

# 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](https://github.com/Field-Robotics-Lab/Bathymetry_Converter).

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