This package contains plugins and models for the simulation of surface vessels in Gazebo.

You will need a working installation of ROS and Gazebo in order to use this package. It has been tested with:

• Gazebo version 9.4.1
• ROS Melodic Morenia
• OSX 10.11.6

Source your ROS installation and update the Gazebo plugin path:

# Source the ROS and Gazebo environment (add this to ~/.bash_profile)
$ source /opt/ros/melodic/setup.bash
$ source /usr/local/share/gazebo/setup.sh

Create and configure a catkin workspace, clone and build the repo:

# Create a catkin workspace 
$ mkdir -p <catkin_ws>/src

# Clone dependencies
$ cd <catkin_ws>/src
$ git clone https://github.com/srmainwaring/asv_wave_sim.git

# Clone this repo
$ git clone https://github.com/srmainwaring/asv_sim.git

# Configure and build
$ cd <catkin_ws>
$ catkin config --extend /opt/ros/melodic \
  --cmake-args -DCMAKE_CXX_STANDARD=14 -DCMAKE_BUILD_TYPE=RelWithDebInfo 
$ catkin build

# Source the workspace
$ source devel/setup.bash

# Update the Gazebo plugin path
$ export GAZEBO_PLUGIN_PATH=$(pwd)/devel/lib:$GAZEBO_PLUGIN_PATH

# Check the Gazebo environment variables
$ printenv |grep GAZEBO

AnemometerSensor to measure wind speed and direction.

Add the SDF for the sensor to a <link> element of your model.

<sensor name="anemometer_sensor" type="anemometer">
  <always_on>true</always_on>
  <update_rate>50</update_rate>
  <topic>anemometer</topic>
</sensor>

1. ~/anemometer (gazebo::msgs::Param_V)

• time (gazebo::msgs::Time)
  The simulation time of the observation.

• true_wind (gazebo::msgs::Vector3d)
  The true wind at the link origin.

• apparent_wind (gazebo::msgs::Vector3d)
  The apparent wind at the link origin (i.e. true wind adjusted for the link velocity).

1. <always_on> (bool, default: false)
   Standard <sensor> parameter. See SDF documentation for details.

2. <update_rate> (double, default: 0)
   Standard <sensor> parameter. See SDF documentation for details.

3. <topic> (string, default: ~/anemometer)
   Standard <sensor> parameter. See SDF documentation for details.

To run the example:

roslaunch asv_sim_gazebo anemometer_demo_world.launch verbose:=true

The launch file loads the RegisterSensorsPlugin system plugin using the parameter:

  <arg name="extra_gazebo_args" default="--server-plugin libRegisterSensorsPlugin.so" />

You should see a world containing a single block at the origin. The figure below shows the block falling to demonstate the effect of motion on apparent wind:

Open the Topic Visualization window and select the anemometer topic:

When the block is at rest with axis aligned with the world frame, the true and apparent wind should be the same. When the block is in motion, for instance by setting the z pose to 100 and letting it fall, the apparent wind will be adjusted for the object's motion.

	Melodic
asv_sim

	Melodic
asv_sim

This is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.