- if using multi-EKF across all magnetometers then an instance of
vehicle_magnetometer is advertised immediately for every sensor_mag
instance
- this can become problematic if EKF2 multi-mag is enabled, but with
only 1 IMU (EKF2_MULTI_MAG) because you will be stuck with no magnetometer data
FW_LND_USETER defaulted to 1 and FW_LND_ABORT terrain based bits all enabled. why? because using a distance sensor is critical to detecting when to flare, and we want to force the user to actively disable these safety settings if they so choose, so that they understand the implications.
- new param, FW_LND_TER_REL
- fixing the glide slope helps keep the landing glide behavior steady (avoiding bumps in the altitude setpoint from e.g. trees)
- flare is still triggered via the distance sensor, if enabled by FW_LND_USETERR
when the vehicle did not track the slope well (e.g. at an offset above the track) and the altitude setpoint flattening on intersection with terrain, the throttle would spool up to smoothly intersect the newly flattened altitude setpoint, this could happen before the flare altitude was reached, which is bad. now the steady state glide behavior will be maintained, and flare can trigger at the appropriate time
- the target_sink_rate param could possibly constrain the maximum commanded sink rate to something less than that of the landing glide slope, which would make it impossible to track. this commit allows opening up the desired max sink rate up to the performance limits of the aircraft, if necessary, for the landing case
- landing slope/curve library removed
- flare curve removed (the position setpoints will not be tracked during a flare, and were being ignored by open-loop maneuvers anyway)
- flare curve replaced by simply commanding a constant glide slope to the ground from the approach entrance, and commanding a sink rate once below flaring alt
- flare is now time-to-touchdown -based to account for differing descent rates (e.g. due to wind)
- flare pitch limits and height rate commands are ramped in from the previous iteration's values at flare onset to avoid jumpy commands
- TECS controls all aspects of the auto landing airspeed and altitude/height rate, and is only constrained by pitch and throttle limits (lessening unintuitive open loop manuever overrides)
- throttle is killed on flare
- flare is the singular point of no return during landing
- lateral manual nudging of the touchdown point is configurable via parameter, allowing the operator to nudge (via remote) either the touchdown point itself (adjusting approach vector) or shifting the entire approach path to the left or right. this helps when GCS map or GNSS uncertainties set the aircraft on a slightly offset approach"
Daniel Agar
Jukka Laitinen
Thomas Stastny
Beat Küng
Thomas Schneider
Peter van der Perk
jasta