AP_NavEKF3: Implement same maths as PX4/ecl EKF
Replace attitude vector states with quaternions
Remove gyro scale factor states
Add XY accel delta velocity bias estimation
Initial tuning
Add GPS body frame offset compensation
AP_NavEKF3: Fix bugs and consolidate aiding switch logic
Switching in and out of aiding modes was being performed in more than one place and was using two variables.
The reversion out of GPS mode due to prolonged loss of GPS was not working.
This consolidates the logic and ensures that PV_AidingMode is only changed by the setAidingMode function.
AP_NavEKF3: prevent multiple fusion mode changes per filter update
AP_NavEKF3: Update tuning defaults
AP_NavEKF3: Fix bug causing switching in and out of aiding
If the GPS receiver was disconnected and no data received, then then the gpsGoodToAlign check did not get a chance to run and becasue it was previously true the EKF would switch back into aiding.
This prevents this by ensuring that gpsGoodToAlign defaults to false when the check is not being performed.
An additional check has also been dded to ensure that there is GPS data to fuse before we declare ready to use GPS.
AP_NavEKF3: Fix bug preventing planes recovering from bad magnetometers
This bug created a race condition whereby if the EKF had to reset the yaw to the GPS ground course to recover from a bad magnetometer, the new heading could be over-written by the bad magnetic heading when the plane reached the height for the scheduled reset.
AP_NavEKF3: Improve switch-over to backup magnetometer
When switching over to a back up magnetometer, ensure that the earth field estimate are reset. Otherwise mag earth field estimates due to the previous failed mag could cause data from the new mag to be rejected.
AP_NavEKF3: enable automatic use of range finder height
AP_NavEKF3: Fix bug in handling of invalid range data
AP_NavEKF3: Fix height drift on ground using range finder without GPSAP_NavEKF3:
AP_NavEKF3: Handle yaw jumps due to core switches
AP_NavEKF3: Enable simultaneous GPS and optical flow use
AP_NavEKF3: fix console status reporting
AP_NavEKF3: send messages to mavlink instead of console
This allows the GCS to better handle the display of messages to the user.
AP_NavEKF3: replace deprecated function call
AP_NavEKF3: Compensate for sensor body frame offsets
AP_NavEKF3: Fix bug in median filter code
AP_NavEKF3: save some memory in the position offsets in EKF3
We don't need to copy that vector3f for every sample. A uint8_t does the job
AP_NavEKF3: Add fusion of range beacon data
AP_NavEKF3: Bring up to date with EKF2
AP_NavEKF3: Misc range beacon updates
AP_NavEKF3: Add mising accessors
AP_NavEKF3: remove duplicate include
AP_NavEKF3: Prevent NaN's when accessing range beacon debug data
AP_NavEKF3: Update range beacon naming
AP_NavEKF3: updates
AP_NavEKF3: miscellaneous changes
AP_NavEKF3: misc updates
AP_NavEKF3: misc range beacons updates
AP_NavEKF3: add missing rover default param
Revert "AP_NavEKF2: Fix bug in published yaw reset value found during code review"
commit 175faf1e41.
Revert "AP_NavEKF2: use a struct for all yaw step class variables"
commit 77fad065d1.
Partially revert "AP_NavEKF2: Handle yaw jumps due to core switches"
commit 885bfd1b4e.
The EK2_RNG_USE_HGT parameter sets the height (expressed as a percentage of the maximum range of the range finder as set by the RNGFND_MAX_CM parameter) below which the range finder will be used as the primary height source when the vehicle is moving slowly.
When using a height reference other than GPS, the height datum can drift due to air pressure changes if using baro, or due to terrain height changes if using range finder as the primary height source. To ensure that a consistent height datum is available when switching between altitude sources, the WGS-84 height estimate of the EKF's local positi norigin is updated using a
single state Bayes estimator,
If rngfinder or gps height data is lost whilst being used, there will be a fall-back to baro data.
Allow different process noise to be set for body (sensor bias) and earth field states.
This allows a stable magnetometer bias estimate to be available at end of flight whilst still allowing for external magnetic anomalies during landing.
Adjust default values to give stable mag bias learning and fast learning of external anomalies.
Automatically use the highest gain consistent with a 5% overshoot to minimise RMS tracking errors.
Provide an alternative correction method for the position and velocity states that allows the user to specify the time-constant. This can be used to fine tune the output observer for for platform specific sensor errors and control loop sensitivity estimation noise.
Change to user adjustable fusion of constant position (as per legacy EKF) instead of constant velocity.
Enable user to specify use of 3-axis magnetometer fusion when operating without aiding.
Don't allow gyro scale factor learning without external aiding data as it can be unreliable
Eliminate the use of horizontal position states during non-aiding operation to make it easier to tune.
Explicitly set the horizontal position associated Kalman gains to zero and the coresponding covariance entries to zero after avery fusion operation.
Make the horizontal velocity observation noise used during non-aiding operation adjustable.
Use a fixed value of velocity noise during initial alignment so that the flight peformance can be tuned without affecting the initial alignment.
Down-sample the IMU and output observer state data to 100Hz for storage in the buffer.
This reduces storage requirements for Copter by 75% or 6KB
It does not affect memory required by plane which already uses short buffers due to its 50Hz execution rate.
This means that the EKF filter operations operate at a maximum rate of 100Hz.
The output observer continues to operate at 400Hz and coning and sculling corrections are applied during the down-sampling so there is no loss of accuracy.
Only applied to interfaces required for data logging.
If an invalid instance is requested, the data for the primary instance is returned. This allows the primary data to be returned by calling with a -1 instance value.
priseborough
Randy Mackay
Andrew Tridgell
Mathieu OTHACEHE
Francisco Ferreira
Jonathan Challinger
Lucas De Marchi
Paul Riseborough