What Is PX4?

PX4 is an open source flight control software for drones and other unmanned vehicles. The project provides a flexible set of tools for drone developers to share technologies to create tailored solutions for drone applications. PX4 provides a standard to deliver drone hardware support and software stack, allowing an ecosystem to build and maintain hardware and software in a scalable way.

Historically, PX4 grew from the PIXHAWK project at ETH Zurich, which the PIXHAWK MAV was specifically designed to be a research platform for computer vision based flight control. The project now counts more than 300 global contributors and is used by some of the world’s most-innovative companies, across a wide range of drone industry applications. The open source community around the Pixhawk open autopilot hardware and the PX4 flight stack is the largest industry-backed development community in the drone space today.

PX4 is part of Dronecode, a non-profit organization administered by Linux Foundation to foster the use of open source software on flying vehicles. Dronecode also hosts QGroundControl, MAVLink & the MAVSDK.

PX4 Features

Modular and extensible architecture
PX4 is highly modular and extensible both in terms of hardware and software. It utilizes a port-based architecture – which means when developers add components, whether it’s individual sensors or using alternate controllers, filters and estimators – the extended system does not lose robustness or performance. All the modules are self-contained and can be easily exchanged against a different module without modifying the core system.
Single code base for all vehicles
PX4 uses the same code paths for different vehicle types. It leverages common sensors and navigation systems, with implementation of airframes-specific controllers for position and attitude. Once a developer understands one vehicle type, it is easy to work on the others without reworking the overall system. Common features are easy to roll out and software can be highly reused and reconfigured for new vehicle types, including multi-rotors, VTOLs, tail-sitters, and more.
Built for autonomy
PX4 is designed with a hybrid system architecture as motivation to deeply couple with embedded computer vision capabilities. Developers working on highly complex autonomous systems leverage the foundation to focus on creating robust localization algorithms.
Broad range of compatible peripherals
Beyond an ecosystem of supported devices, PX4 offers optimised APIs and SDKs for developers working with integrations. This significantly lowers the barriers for those who are accustomed to non-embedded toolkits to implement custom payload solutions.
Flexible and powerful flight modes
Great safety features including automated failsafe behaviour, support for different return modes, parachutes etc. are already included in the codebase. The different flight modes are configurable and tunable.
Companion development tools
PX4 provides various companion open source development tools such as web-based flight log analysis for sensor data visualization, dynamics simulation with high performance physics engines.
Developed on open innovation model
PX4 is co-developed with a global development community. The design is not just fulfilling the needs of one lab or company, but has been intended as a general toolkit and is widely used and adopted in the industry. There is a vibrant community behind the project to provide support.
Validated by real world systems tests
Thousands of PX4 based systems have been deployed worldwide. In parallel, PX4 partners with Dronecode’s dedicated flight test team clocking up thousands of flight hours each month running hardware and software tests to ensure safety and reliability.
Industry friendly permissive license
PX4 is free to use and modify under the terms of the permissive BSD 3-clause license.

PX4 Adopters