Originally posted on DIY Drones by Andrew Tridgell.
The ArduPilot development team is proud to announce the release of the first beta version of the 3.5.0 release of APM:Plane. We think this is going to be a great release and we’d love some feedback before we do the final version.
The biggest changes in this release are:
- switch to new EKF2 kalman filter for attitude and position estimation
- added support for parachutes
- added support for QuadPlanes
- support for 3 new flight boards, the QualComm Flight, the BHAT and the PXFmini
- support for arming on moving platforms
New Kalman Filter
The 3.4 release series was the first where APM:Plane used a Kalman Filter by default for attitude and position estimation. It works very well, but Paul Riseborough has been working hard recently on a new EKF variant which fixes many issues seen with the old estimator. The key improvements are:
- support for separate filters on each IMU for multi-IMU boards (such as the Pixhawk), giving a high degree of redundency
- much better handling of gyro drift estimation, especially on startup
- much faster recovery from attitude estimation errors
After extensive testing of the new EKF code we decided to make it the default for this release. You can still use the old EKF if you want to by setting AHRS_EKF_TYPE to 1, although it is recommended that the new EKF be used for all aircraft.
Parachute Support
This is the first release with support for parachute landings on plane. The configuration and use of a parachute is the same as the existing copter parachute support. See http://copter.ardupilot.com/wiki/parachute/
Note that parachute support is considered experimental in planes.
QuadPlane Support
This release includes support for hybrid plane/multi-rotors called QuadPlanes. More details are available in this blog post: http://diydrones.com/profiles/blogs/quadplane-support-in-apm-plane-…
Support for 3 new Flight Boards
The porting of ArduPilot to more flight boards continues, with support for 3 new flight boards in this release. They are:
- the BHAT board
- the PXFmini
- the Qualcomm Flight
More information about the list of supported boards is available here: http://ardupilot.org/copter/docs/common-autopilots.html/
Startup on a moving platform
One of the benefits of the new EKF2 estimator is that it allows for rapid estimation of gyro offset without doing a gyro calibration on startup. This makes it possible to startup and arm on a moving platform by setting the INS_GYR_CAL parameter to zero (to disable gyro calibration on boot). This should be a big help when flying off boats.
That is just a taste of all of the improvements in this release. In total the release includes over 1500 patches. Some of the other more significant changes include:
- RPM logging
- new waf build system
- new async accel calibrator
- SITL support for quadplanes
- improved land approach logic
- better rangefinder power control
- ADSB adapter support
- dataflash over mavlink support
- settable main loop rate
- hideable parameters
- improved crash detection logic
- added optional smooth speed weighting for landing
- improved logging for dual-GPS setups
- improvements to multiple RTK GPS drivers
- numerous HAL_Linux improvements
- improved logging of CAM messages
- added support for IMU heaters in HAL_Linux
- support for RCInput over UDP in HAL_Linux
- improved EKF startup checks for GPS accuracy
- added raw IMU logging for all platforms
- added BRD_CAN_ENABLE parameter
- support FlightGear visualisation in SITL
- configurable RGB LED brightness
Many thanks to everyone who contributed to this release! The development team is growing at a fast pace, with 57 people contributing changes over this release cycle.
I’d like to make special mention of Tom Pittenger and Michael du Breuil who have been doing extensive testing of the plane development code, and also contributing a great deal of their own improvements. Thanks!
