This removes errors in the in-flight reset of the earth field states by:
1) Using a state vector and magnetometer measurement from the same time coordinate
2) Not using the AHRS trim offsets in the calculation
dtIMUactual has been spit into a separate dtDelAng and dtDelVel and dtDelVel1 and dtDelVel2 delta time in recognition of the amount of timing jitter and different update rates for the IMU's
Vibration in the 400Hz delta angles could cause the angular rate condition check for in-flight magnetic field alignment to fail.
The symptons were failure to start magnetic field learning as expected when EK2_MAG_CAL=3 was set.
The calculation of a delta rotation between consecutive magnetometer samples has been introduced instead of the most recent IMU delta angle as this is less affected by noise and give an upper bound on the angular error.
the check has been moved into the magnetometer fusion control function so that any reset will be performed using fresh magnetometer data
Explicitly set Plane parameters rather than rely on use of the default
If no type defined, default to Copter parameters (most common platform type
Enable different platform types to use different initial accel bias uncertainty
Reduce initial accel bias uncertainty for copter to prevent initial oscillation in bias and height estimate
Large baro data errors when flying without GPS could cause total failure of the EKF.
This patch provides protection against this happening in-flight but allows for large innovations during preflight alignment.
Now variables don't have to be declared with PROGMEM anymore, so remove
them. This was automated with:
git grep -l -z PROGMEM | xargs -0 sed -i 's/ PROGMEM / /g'
git grep -l -z PROGMEM | xargs -0 sed -i 's/PROGMEM//g'
The 2 commands were done so we don't leave behind spurious spaces.
AVR-specific places were not changed.
Now that we are using a consistent 50Hz minimum update rate for the covariance prediction we do not need a different initial gyro bias uncertainty for plane and copter to maintain filter stability margins.
The default value of 0.1 rad/s was too high and gave excessive settling time of the filter attitude after startup.
The initial attitude uncertainty has been increased to allow for some movement during startup.
If the baro data and magnetometer data are interleaved (arriving every 100 msec and offset by 50 msec), then the filter will go unstable during startup and fail to complete checks.
Fixes a potential error where changes to timing and arrival rate of magnetometer and baro data could block the fusion of synthetic position and velocity measurements, allowing unrestrained tilt errors during operation without GPS or optical flow.
Fusion of synthetic position or velocity measurements is now timed to coincide with fusion of barometer observations.
If a new barometer observation has not arrived after 200 msec then the synthetic position or velocity is fused anyway so that fusion of synthetic position or velocity observations cannot occur any slower than 5 Hz
Previous check default only checked the number of satellites and horizontal position accuracy.
Updated default value also checks HDoP and speed accuracy.
Luis Vale Gonçalves
Paul Riseborough
Siddharth Bharat Purohit
Andrew Tridgell
Lucas De Marchi
Randy Mackay
Gustavo Jose de Sousa
Jonathan Challinger
Tom Pittenger