Plane speed control auto landing

ArduPlane Plane 4.5
1

Hello!
I’ve implemented reverse thrust for speed reduction purposes.
I use SpeedyBee F405 Wing on Volantex Phoenix 2000. Lidar and airspeed also set up as recommended. However the plane (glider) always maintain cruise speed 12m/s while auto landing until touchdown. I’ve tried different airspeed, even manually reduce the speed before landing, but ardupilot would increase it back to 12m/s. What am I missing?
Here are some of my params:
RNGFND_LANDING = 1
TECS_LAND_ARSPD = 5
LAND_PF_ARSPD = 7
LAND_FLARE_SEC = 1.5
LAND_FLARE_ALT = 2
AIRSPEED_MIN = 12
USE_REV_THRUST = 6146

Please give me some hints what to chek or maybe the parameters are set wrong.

2

What type of ESC do you have?
Does your ESC support reverse thrust?
Post the ESC configuration that references reverse thrust?

3

ESC_Graupner
ESC_Graupner958×758 160 KB

ESC is this one: Graupner ULTRA CONTROL 35A 2-4S BLHELI SBEC S3083.3D
I’ve manually configured it to enable the reverse thrust and successfully tested it on the bench. Manual and FBWA control also allows reverse braking when RC is below middle value. It works during flight (it makes distinguish noise when active).

4

Welcome to the forum,

Reverse throttle as well as autolanding is a complex thing, a link to a *.bin logfile of a flight with autoland would be really helpful to help you.

Rolf

5

From the documentation it is understood that LAND_PF_ARSPD is LESS than TECS_LAND_ARSPD.

The data you have configured does not comply.

Precision AutoLanding — Plane documentation

6

Thank you for pointing that out! I will change required speed accordingly and test next weekend.
From the logs I see that demanded airspeed was always 12m/s until touch down.