PX4 Developer Summit | Zurich 2019

As we work towards integrating more advanced functionality into drones it's important to be able to test them. We have been working toward improving supporting multi drone simulation as well as complex worlds to support sensor based autonomy in SITL and fully automated integration tests.

As we look towards more complex systems, PX4-powered UAS will become a subsystem in a larger system. With the current developments of ROS 2 and its infrastructure, the demand to make PX4 capable of integrating with such framework has increased, besides the current already supported ROS-Mavlink bridge package, MAVROS. The ability to isolate telemetry links over Mavlink and provide a more tight integration of the PX4 internal communication architecture with the companion systems lead us to explore the benefits of DDS (Data Distribution Service) standard and, for that reason, implement a bridge that allows PX4 uORB publisher/subscriber architecture to connect to RTPS (Real Time Publish-Subscribe) protocol participants over the same DDS standard layer, while looking to gradually abandon the usage of Mavlink in companion computer links. As being the default middleware of ROS2, eProsima Fast-RTPS was the chosen RTPS implementation to bridge PX4 uORB topics with ROS 2 nodes.

This presentation will show how the px4_ros_com, a ROS2 package for bridging PX4 and ROS2 through a micro-RTPS bridge - a slimmed down RTPS point-to-point link using micro-RTPS (client/FCU side) and Fast-CDR (agent/companion side) for serialization and deserialization - is architectured and implemented, how can it be used and provide an overall status about its current development state and future works. It will also be provided a pros/cons comparison between using RTPS-supported and Mavlink-supported communication in PX4 and companion computer links.