Gazebo Classic

In this section, we will explain how to install and setup Gazebo Classic and PX4-Autopilot for performing simulations with pegasus. This was tested on Ubuntu 22.04.

Installing Gazebo Classic

Start by installing gazebo classic. Make sure that you do not have the gz-garden package installed, as it may conflict with the installation of gazebo classic.

# Make sure to uninstall gazebo garden (if installed)
sudo apt remove gz-garden
sudo apt install aptitude

# Install gazebo (classic)
sudo aptitude install gazebo libgazebo11 libgazebo-dev

# Install the ROS packages for gazebo
sudo apt install ros-humble-gazebo-ros ros-humble-gazebo-ros-pkgs

Installing PX4-Autopilot

In this first version of the Pegasus the PX4-Autopilot is used for handling motor control and sensor integration. To install PX4-Autopilot, follow the following steps:

1. Install the dependencies (to be able to compile PX4-Autopilot):

   # Linux packages
   sudo apt install git make cmake python3-pip
   
   # Python packages
   pip install kconfiglib jinja2 empy jsonschema pyros-genmsg packaging toml numpy future
   
   # GStreamer (for video streaming)
   sudo apt-get install libgstreamer-plugins-base1.0-dev gstreamer1.0-plugins-bad gstreamer1.0-plugins-base gstreamer1.0-plugins-good gstreamer1.0-plugins-ugly -y
   

2. Clone the PX4-Autopilot:

   # Option 1: With HTTPS
   git clone https://github.com/PX4/PX4-Autopilot.git
   # Option 2: With SSH (you need to setup a github account with ssh keys)
   git clone git@github.com:PX4/PX4-Autopilot.git
   

3. Checkout to the stable version 1.14.3 and compile the code for software-in-the-loop (SITL) mode:

   # Go to the PX4 directory
   cd PX4-Autopilot
   
   # Checkout to the latest stable release
   git checkout v1.14.3
   
   # Compile the code in SITL mode
   make px4_sitl gazebo-classic
   

4. Add the following line to your .bashrc file:

   echo "export PX4_DIR=$(pwd)" >> ~/.bashrc
   

   Note

   Adding this line to the .bashrc file is important as the Pegasus Gazebo package will need to know the location of the PX4-Autopilot directory, and the launch files will use this environment variable to find the necessary files.

Installing the Pegasus Gazebo package

1. In the Pegasus workspace, clone the following repository:

   # Go to the src folder of the Pegasus workspace
   cd ~/pegasus/src
   
   # Clone the repository (SSH)
   git clone git@github.com:PegasusResearch/pegasus_gazebo.git
   

2. Compile the code:

   # Go to the workspace
   cd ~/pegasus
   
   # Compile the code
   colcon build --symlink-install
   

3. Source the workspace in the .bashrc file:

   echo "source ~/pegasus/install/setup.bash" >> ~/.bashrc
   

Running a Simulation

To run a simulation with the Pegasus Gazebo package, follow the steps below:

1. Start the gazebo server with a world file:

   ros2 launch pegasus_gazebo taguspark.launch.py
   

2. On another terminal, start a vehicle simulation:

   ros2 launch pegasus_gazebo iris.launch.py vehicle_id:=<vehicle_id>
   

   You should replace the <vehicle_id> with the vehicle id you want to connect to. If no option is provided, the vehicle will run with ID 1.

3. On a third terminal, start the pegasus console to operate the vehicle:

   ros2 run pegasus_console pegasus_console
   

   Pegasus Console

   Check the Terminal console page for more information on how to operate the vehicle.

World launch files available for simulation:

• taguspark.launch.py: A simple world with a “box” the size of the Taguspark Mocap Arena.

• empty.launch.py: An empty world with no obstacles (for low-weight simulations).

Vehicle launch files available for simulation:

• iris.launch.py: A simple Iris drone.

• iris_fpv.launch.py: A simple Iris drone with a front-facing monocular camera.