At the Zurich PX4 DevSummit 2 weeks ago, the PX4 maintainers celebrated the release of PX4 version 1.9 with the community. This latest release is the result of work by hundreds of developers over the last 8 months (there have been more than 3000 commits since PX4 v1.8.2 was released in November 2018).

What has improved?
  • Smoother transitions through waypoints using a new jerk-limiting control mode
  • Disturbance rejection with more aggressive motor output mixing
  • Smoother takeoff and landing
  • Better out-of-the-box experience for larger vehicles (filtering low frequency vibrations by default on larger vehicles)
  • Reliable vehicle heading measurement in magnetically challenging environments – using RTK GPS instead of a magnetometer
  • Significant improvements for VTOL wind handling, takeoff and landing using the weathervane feature
  • Collision prevention in Position mode (slows/stops a vehicle before it can hit an obstacle)
  • Obstacle avoidance in missions, along with failsafe and pre-flight checks to ensure that the avoidance system is running and healthy


What are the advantages for the developers?

  • Flight tasks provide a simpler and safer interface for adding new flight behaviour
  • The trajectory interface integration into mission mode allows developers to seamlessly blend route planning from an offboard computer into missions running on the flight controller. The obstacle avoidance implementation currently uses this feature!
  • Simulation lockstep between SITL and Gazebo or JMAVSim allows PX4 simulation to run better on less powerful hardware. As a side-benefit simulation can now be run faster (or slower) than realtime, speeding up tests.


What are the advantages for pilots?

  • New orbit flight mode is useful for capturing video/images of a target as you go around it (e.g. if a drone flying towards a lighthouse and circling it)
  • Multicopters by default will fly smoother, enabling better user experience
  • Seamless integration of obstacle avoidance into planning and flying missions
  • Both collision prevention and obstacle avoidance increase flight safety


Where can I find out more info?

The full changelog can be found here: