Otter ROS

Overview

Otter ROS is a ROS2 driver for the Maritime Robotics Otter USV, intended to be run on a secondary computer system to communicate with the proprietary hardware on the vessel. It is intended for research purposes and in development by the Offroad Robotics research group at Ingenuity Labs at Queen’s University.

Please see accompanying message package Otter Msgs for more information on custom messages used in Otter ROS.

A few controllers have also been included that are based on the work of Thor I. Fossen in the book Handbook of Marine Craft Hydrodynamics and Motion Control and his accompanying MatLab simulator Marine Systems Simulator (MSS) and Python simulator PythonVehicleSimulator.

Ensure communications with the Otter USV before launching Otter ROS. Edit config/otter_params.yaml to match networking setup.

Keywords: otter usv, usv driver, maritime robotics, ros2, python, nmea, navigation, control

License

The source code is presently unlicensed.

Authors: Riley Cooper, Sabrina Button, Thomas Sears, Joshua Marshall
Acknowledgements: Thor I. Fossen
Affiliation: Offroad Robotics, Queen’s University
Maintainer: Sabrina Button, sabrina.button@queensu.ca

The Otter ROS package has been tested under [ROS2] Foxy on Ubuntu 20.04, interfaced with a Maritime Robotics Otter USV equipped with a VLP-16 LiDAR. This is research code, expect that it changes often and any fitness for a particular purpose is disclaimed.

Installation

Building from Source

Dependencies

• Robot Operating System 2 (ROS2) (middleware for robotics),

• Velodyne (LiDAR driver) - OPTIONAL, remove from launch files if not using

    sudo rosdep install --from-paths src
  

Building

To build from source, clone the latest version from this repository into your catkin workspace and compile the package using

cd ros2_ws/src
git clone https://code.engineering.queensu.ca/offroad/otter-ros.git
cd ../
rosdep install --from-paths . --ignore-src
colcon build

Usage

Run the main nodes (+ velodyne driver) with

ros2 launch otter_ros otter_launch_base.py

NMEA Input

• MARGPS: otter lat, lon, alt, sog, cog, hog
• MARIMU: otter roll, pitch, yaw, p,q,r
• MAROTR: otter port and starboard motor rpm, temp and power, as well as total power and number of batteries

Config files

otter_params.yaml

This file contains the parameters for the Otter ROS driver. The default values are set for the Otter USV. The parameters are:

• socket: entry socket for otter, defaults to 2009
• ip_address: ip for otter, defaults to
• frame_id: frame id for the odometry messages

ekf_with_gps.yaml

This file contains the parameters for the robot_localization navsat transform. The default values are set for the Otter USV. The most important parameter is:

• magnetic_declination: magnetic declination of the USV’s operating environment, defaults to 0.141953445247 (Kingston, Ontario, July 2023)

Launch files

This folder contains launch files for the otter_ros package.

• otter_launch_nmpc: launches pub,sub for otter and an NMPC controller node developed by Riley Cooper.

  • autobag: records all topics to a bag file by default. Set to false to disable.
  • bag_name: name of bag file to record to. Defaults to “/mnt/data/otter_ros_default_bag”.
  • wpt_file: path to waypoint file. Defaults to None.
• otter_sys_id_test_launch: a launch file created for testing in dec 2021 and launches the test plan file created for this testing on top of pub, sub for the otter.
• otter_heading_control_launch: launches pub,sub for otter and a controller node.
• otter_navsat_transform_launch: launches a navsat transform for the otter which converts otter_imu and otter_gps to an otter_odom Odometry message. Should be launched concurrently with otter_launch.

Nodes

otter_publisher

This node handles all the data being transmitted from the Otter OBS system. The data comes over TCP port 2009 (by default).

Published Topics

• /otter_status (otter_msgs/OtterStatus): MAROTR data

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