TECS does not use the external HAGL set by the AP_MAVLINK_MAV_CMD_SET_HAGL_ENABLED subsystem.
Instead, it uses Plane::height_above_target(), which is not made aware of this information.
Issue details
This aircraft uses a Lua script to read a lidar and feed the distance to ground via the MAV_CMD_SET_HAGL message.
There are two logs attached, with automated landings with flares:
One where the landing was good and the plane flared in time: log_good
One where the flare was very delayed and the operator tried to take over: log_bad
timeline:
(Altitudes are from rangefinder, RNFD[0].Dist, unless otherwise specified.)
No RNGFND_LANDING enabled, because external HAGL setting is used.
In the bad log, the plane comes down relatively fast at ~5m/s sink rate.
The good log has ~2.5m/s.
B: The preflare triggers at 25m via LAND_PF_ALT.
G: The good log triggers at 25m via LAND_PF_ALT.
B: Pitch angle is very negative at -20deg.
G: The good flight has around -12deg.
B: Flare is triggered at 10m via LAND_FLARE_SEC.
G: In the good flight is triggered at 8.8m via LAND_FLARE_SEC.
B: TECS gradually reduces the sink rate as the HAGL (and hence TECS Above Field Elevation) reduces from 13.5m to 6m.
G: In the good log the sink rate is immediately set to 0.6m/s, because the HAGL (and hence TECS Above Field Elevation) is 0.97m < 6m.
Bug report
Summary
TECS does not use the external HAGL set by the
AP_MAVLINK_MAV_CMD_SET_HAGL_ENABLEDsubsystem. Instead, it usesPlane::height_above_target(), which is not made aware of this information.Issue details
This aircraft uses a Lua script to read a lidar and feed the distance to ground via the
MAV_CMD_SET_HAGLmessage.There are two logs attached, with automated landings with flares: One where the landing was good and the plane flared in time: log_good One where the flare was very delayed and the operator tried to take over: log_bad
timeline: (Altitudes are from rangefinder,
RNFD[0].Dist, unless otherwise specified.) NoRNGFND_LANDINGenabled, because external HAGL setting is used.In the bad log, the plane comes down relatively fast at ~5m/s sink rate. The good log has ~2.5m/s.
B: The preflare triggers at 25m via
LAND_PF_ALT. G: The good log triggers at 25m viaLAND_PF_ALT.B: Pitch angle is very negative at -20deg. G: The good flight has around -12deg.
B: Flare is triggered at 10m via
LAND_FLARE_SEC. G: In the good flight is triggered at 8.8m viaLAND_FLARE_SEC.B: TECS gradually reduces the sink rate as the HAGL (and hence TECS Above Field Elevation) reduces from 13.5m to 6m. G: In the good log the sink rate is immediately set to 0.6m/s, because the HAGL (and hence TECS Above Field Elevation) is 0.97m < 6m.
Screenshot from the bad log:
Version 4.6.0dev
Platform [ ] All [ ] AntennaTracker [ ] Copter [X] Plane [ ] Rover [ ] Submarine
Airframe type Normal plane with back-mounted lidar for inverted landing.
Hardware type Cube Orange+
Logs Please provide a link to any relevant logs that show the issue