Multi-Vehicle Sim

This topic explains how to simulate multiple UAV vehicles using Gazebo (Gz) and SITL.

:::note Multi-Vehicle Simulation with Gazebo is only supported on Linux. :::

Gazebo makes it very easy to setup multi-vehicle scenarios (compared to other simulators).

First build PX4 SITL code using:

make px4_sitl

Each instance of PX4 can then be launched in its own terminal, specifying a unique instance number and its desired combination of environment variables:

ARGS ./build/px4_sitl_default/bin/px4 [-i <instance>]

  • <instance>: The instance number of the vehicle.

    • Each vehicle must have a unique instance number. If not given, the instance number defaults to zero.

    • When used with PX4_GZ_MODEL, Gazebo will automatically pick a unique model name in the form ${PX4_GZ_MODEL}_instance.

  • ARGS: A list of environmental variables, as described in Gazebo Simulation > Usage/Configuration Options.

This allows for greater flexibility and customization.

Multiple Vehicles with ROS 2 and Gazebo

Multiple vehicles with ROS 2 are possible.

  • First follow the installation instructions for Gazebo.

  • Then configure your system for ROS 2 / PX4 operations.

  • In different terminals manually start a multi vehicle simulation. This example spawns 2 X500 Quadrotors and a fixed wing:

    PX4_SYS_AUTOSTART=4001 PX4_GZ_MODEL=x500 ./build/px4_sitl_default/bin/px4 -i 1
    PX4_SYS_AUTOSTART=4001 PX4_GZ_MODEL_POSE="0,1" PX4_GZ_MODEL=x500 ./build/px4_sitl_default/bin/px4 -i 2
    PX4_SYS_AUTOSTART=4004 PX4_GZ_MODEL_POSE="0,2" PX4_GZ_MODEL=rc_cessna ./build/px4_sitl_default/bin/px4 -i 3

  • Start the agent:

    MicroXRCEAgent udp4 -p 8888

    The agent will automatically connect to all clients.

  • Run ros2 topic list to see the topic list, which should look like this:

PreviousVehiclesNextGazebo Classic Simulation

Last updated