PX4 Autopilot Flight Controller¶

The PX4 Autopilot software stack is a very popular open-source flight controller with support for a wide variety of boards and sensors as well as a built-in capability for higher level tasks such as mission planning. Please visit px4.io for more information.

Warning: While all releases of Project AirSim support PX4, setting up PX4 is not trivial. It may be easier to start with Simple Flight, the flight controller that comes with Project AirSim, before attempting to use PX4.

Supported versions of PX4¶

Project AirSim supports PX4 v1.12.3. Other versions may work but are unsupported.

Software-In-The-Loop (SITL)¶

The recommended way to use PX4 with Project AirSim is “Software In The Loop” or SITL. In this configuration, the PX4 software stack is running as a program on a PC and communicating with Project AirSim on the same computer or another computer on the local network.

See Use PX4 as Software In The Loop for setup and use.

Hardware-In-The-Loop (HITL)¶

Project AirSim also supports using PX4 as “Hardware In The Loop” or HITL. In this configuration the PX4 software stack is running on a dedicated controller board and communicating with Project AirSim via USB. Project AirSim requires that the PX4 hardware supports the MAVLink protocol over USB and runs a supported version of the PX4 firmware.

See Use PX4 as Hardware In The Loop for setup and use.

Which configuration?¶

The following table compares using Project AirSim with PX4 in the SITL and HITL configurations:

Feature	SITL (Recommended)	HITL
PX4 Device	No	Required
Manual Flight	Via game controller or RC transmitter over USB	Optional via RC transmitter & receiver
Airframes	All Project AirSim airframes	“HIL Quadcopter X” only
Setup & Run	Harder	Easier
Modifying/Debugging PX4 Software	Easier	Harder