The previous method resulted in data incest and fusion of predicted airspeed on every EKF internal time step.
This was not apparent during flight where the vehicle was turning, but during long straight legs did not constrain along track drift.
These changes enable the EKF to use the last observable wind velocity vector estimate to synthesise an airspeed measurement if operating without an airspeed sensor and when all other measurement types that can constrain velocoty drift are lost. This enables the EKF to use dead reckoning to continue after loss of GPS when there is no air speed sensor fitted and without the need to set a default airspeed value.
The logic used to fuse a default airspeed value has also been cleaned up and the call to FuseAirSpeed() from inside SelectBetaDragFusion() has been removed.
AP_NavEKF3: Fix error in default airspeed observation variance
AP_NavEKF3: Enable shadow fusion of airspeed when sensor is disabled
filter status was initially set to zero then updated. This interacts
with the IMU filtering code which checks filter status from a
different thread to determine active_EKF_type(). When the race
condition is hit then the IMU we are running notch filters on changes
for a single sample, causing a notch filter glitch
Innovations and innovation test ratios will still be calculated and reported for an unhealthy sensor, but the EKF states wnd covariance matrix will not be modified.
When returning our last-known-position we were supplying lat/lng but not
altitude.
This usually really doesn't matter as this result generally isn't used,
especially for altitude. OTOH, it may prevent a bug into the future.
Fixes bug that prevents the vertical velocity being reset to the GPS if the position aiding has already timed out and improves sensitivity of the bad IMU data check.
this shifts EKF_origin to the current location at 1Hz, while leaving
public_origin alone. All output APIs and logging are relative to
public_origin.
The effect of this change is to remove the distortion caused by a
spherical earth, which allows the EKF to operate without errors at
very long distances from the public_origin.
MAG_CAL param description include deprecated values
Pre-arm check of MAG_CAL using deprecated values
effective_magCal interprets 5 (was EXTERNAL_YAW) as Never, 6 (was EXTERNAL_YAW_FALLBACK) as WhenFlying
Update comments in param conversion from MAG_CAL to EK3_SRC1_YAW
Paul Riseborough
Paul Riseborough
Randy Mackay
Andrew Tridgell
Peter Barker
Josh Henderson
Patrick José Pereira