Landing flare does not work

ArduPlane Plane 4.0
1

Hello,
I am trying to setup my Lidar to use it for landing, in order to have a proper flare before the aircraft touches the ground.

The thing is, despite the parameters, the aircraft does not flare. Sometime it does, but sometime it doesn’t and it touches the ground very abruptly.

Here you have the video of the landing : https://www.youtube.com/watch?v=RGNq01AxNAQ&feature=youtu.be

And here you have the logs : https://www.dropbox.com/sh/41llq9pbwve291c/AAAjhML26LpOdT2YeuCUwWcua?dl=0

The main thing is not the Lidar. It is the Flare. Whether Ardupilot uses the Lidar or not, the problem is that the aircraft is not flaring.
Once the flare problem is solved, I can focus on the Lidar.

So, what am I doing wrong ?
Of course, I have read every documentation concerning the landing.
Thank you

P.S. : I am using latest MP and firmware

2

Hi Nicolas,

Your plane is porpoising during approach.
You run stock PID settings. These are good for initial flights but not sufficient for a steady approach.

bad_approach
bad_approach1202×664 66.8 KB

Recommended solution:

  1. Run Autotune first to improve the flight controller performance. Hint: take a day with low winds.
  2. Check the behavior by some test approaches without a real landing (for example from 50 meters down to 10 meters and go around. You want a steady descent rate between 1 and 2m/s.
  3. You may need some TECS tuning as well.
  4. Switch back all LAND_ parameters back to default (for non Lidar landings) and try the first auto landings on barometer only until you got the basics. For the short flights the barometer only should be fine.
    You may alter LAND_FLARE_SEC by half second steps from default to fit your needs.

Good luck!!

3

Thank you very mulch for that complete answer !
I will do the things you said, and come back to you when it’s done. Thank you !