The ardupilot development team is proud to announce the release of version 3.0.3 of APM:Plane. This release contains some important bug fixes for all supported boards.
The key bug fixes in this release are:
fixed handling of filter divergence in the EKF filter
fixed a glide slope calculation bug when entering AUTO mode
The EKF fixes are the main focus of this release. During testing of APM:Plane with the AHRS_EKF_USE enabled it was found that under some circumstances the EKF could diverge, resulting in loss of attitude estimate. Unless the pilot quickly took control in MANUAL this could result in the aircraft crashing.
The fix for this problem was in several parts. The main fix was to prevent the divergence, but as a precaution against future bugs of this type additional numerical checks were added to allow the EKF to automatically reset in flight when the internal state shows large gyro bias changes, which are the first sign of something going wrong in the filter. If this happens again the EKF will automatically disable itself for 10 seconds, allowing APM:Plane to fall back to the old DCM code. The EKF will then reset itself using initial state based on the DCM state. The aircraft will report the failure using the AHRS health bit in the SYS_STATUS MAVLink message.
Alan is serial entrepreneur, active angel investor, and a drone enthusiast. He co-founded DRONELIFE.com to address the emerging commercial market for drones and drone technology. Prior to DRONELIFE.com, Alan co-founded Where.com, ThinkingScreen Media, and Nurse.com. Recently, Alan has co-founded Crowditz.com, a leader in Equity Crowdfunding Data, Analytics, and Insights. Alan can be reached at alan(at)dronelife.com