PX4: A node-based multithreaded open source robotics framework for deeply embedded platforms

TLDR

The framework leverages common Unix knowledge and a bash‑like shell to enable reuse of familiar tools. We present a novel, deeply embedded robotics middleware and programming environment. It employs a multithreaded publish‑subscribe design with a POSIX‑based object request broker, offering a Unix‑like interface and direct ROS integration for native or micro‑controller nodes. The modular, standards‑oriented platform outperforms existing deeply embedded open‑source systems, delivering lower latency, better hardware connectivity, and suitability for VTOL experiments.

Abstract

We present a novel, deeply embedded robotics middleware and programming environment. It uses a multithreaded, publish-subscribe design pattern and provides a Unix-like software interface for micro controller applications. We improve over the state of the art in deeply embedded open source systems by providing a modular and standards-oriented platform. Our system architecture is centered around a publish-subscribe object request broker on top of a POSIX application programming interface. This allows to reuse common Unix knowledge and experience, including a bash-like shell. We demonstrate with a vertical takeoff and landing (VTOL) use case that the system modularity is well suited for novel and experimental vehicle platforms. We also show how the system architecture allows a direct interface to ROS and to run individual processes either as native ROS nodes on Linux or nodes on the micro controller, maximizing interoperability. Our microcontroller-based execution environment has substantially lower latency and better hardware connectivity than a typical Robotics Linux system and is therefore well suited for fast, high rate control tasks.