A ROS 2 Library and Interface for External PX4 Flight Modes - Thomas Stastny & Beat Küng, Auterion

This talk will introduce a library and interface for writing ROS2 applications that control a drone running PX4. Applications may include high-level navigation tasks all the way down to direct actuator controls. However, this framework goes much further than the existing MAVLink-based "offboard" mode. Here, ROS2 modes are registered as first class citizens, behaving the same as an FMU-internal mode, communicating directly over uORB messaging, providing their own arming checks and mode requirements, fully integrated into the failsafe state machine, and with clear rules for who is control, with well defined control setpoints. We will discuss several key concepts around the library and interface including definitions of flight modes, flight mode executors (think the PX4 Navigator module, but easier to work with, and more powerful), and control interfaces. We will follow the conceptual discussion with some examples and demonstrations showcasing the current state of the library, and where we would like to see it progress in the future.