Adapted from EKF2 implementation as of commits
3835d2613, e9ed3540f and df4fc0fff
this sets a limit on the difference between the earth field from the
WMM tables and the learned earth field inside the EKF. Setting it to
zero disables the feature. A positive value sets the limit in mGauss.
this moves intermediate variables from being per-core to being common
between cores. This saves memory on systems with more than one core by
avoiding allocating this memory on every core.
This is an alternative to #11717 which moves memory onto the stack. It
doesn't save as much memory as #11717, but avoids creating large stack
frames
this prevents the EKF origin on different cores from being initialised
to different values. A common value is stored in the frontend and used
by a core if it doesn't have an origin
This avoids creating two pointers of different types to the same memory.
Having two pointers to the same memory can lead to the compiler
optimising code such that a write to one pointer is rearranged to be
either before or after a read from the other pointer depending on
which is deemed faster - not a good outcome.
To eliminate the possibility of editing errors, revert the covariance prediction auto-code to the original auto-code without the replacement fo the /2 and /4 operations. The compiler optimisations are able to correctly handle the /2 and /4 operations.
Also use local variables for intermediate covariance calculations. The use of class variables for these small arrays was unnecessary.
This patch ensures that covariance matrix entries for inactive states are always set to zero.
It also halves the number of copy operations from the updated to stored matrix.
Fix rounding error bug preventing state from updating after initial convergence.
Decouple GPS reference height from published EKf origin height.
Add bitmask parameter to control update and publishing of GPS reference height.
this changes the stragegy for load levelling between EKF cores so it
works between EK2 and EK3, and with future estimators as well.
It allows us to run EK3 and EK2 at the same time with good scheduling
performance
If the GPS receiver selection changes and we are using GPS for height, the vertical position will be reset to the new GPS height measurement.
correct output observer history when doing a GPS height reset
Copter operation without a magnetometer is limited to constant position and relative position modes only (no GPS or range beacon fusion permitted)
Copter optical flow operation without a magnetometer is permitted.
The ability of planes to takeoff/launch without a magnetometer and align the yaw using the GPS velocity is retained.
Use the time delay returned by the GPS driver.
Wait long enough for the GPS configuration to be determined, but time out after 30 seconds and warn the user that a default value for time delay will be used.
