Success! I’ll post more details, but I wanted to thank you specifically, because changing the landing glide slope was the key to getting the plane on the ground without bending the landing gear. Thank you!
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I’ve ordered a LIDAR and airspeed sensor, @RizHass , but I’ve noticed that Arduplane actually has a very good understanding of the correct altitude and headwind, I don’t think the input data is the problem actually.
Here is the successful flight. It’s a different plane running a PixRacer.
Log: Dropbox - log_36_2022-3-8-18-11-32.bin - Simplify your life
Video: AeroRacer Maiden Autonomous Mission. Hands free Takeoff and landing thanks to ArduPlane. - YouTube
The FC seems to have all the correct data, but what confuses me when I view this in the UAV log viewer is the plane ends up “underground”, I think if it landed at ground level it would have been perfect.
It needs the LIDAR to measure where the ground is on landing. The basic problem is barometric altitude will change over time, so the time your plane comes back around to land it could be off by a couple of meters, so it requires the LIDAR to correct for that otherwise it’s going to try and land where it thinks the ground is based on the barometric data it recorded when it took off.
You also have the issue of ground effect, as the plane comes down to land it’s going to cause a high pressure zone under the aircraft that will affect the barometric sensor, causing it to think it’s climbing again.
Air speed sensor does help make landings more accurate as it can help regulate speed much better than just the estimation and is very useful for steep reverse thrust landings, but in very gusty conditions I would disable it. I found that it wasn’t smart enough to handle head on gusts, so it would throttle back thinking it was over speeding and stall.
You can put slew rate limits on the throttle to try and get though the smaller gusts but when it’s really gusty there is a setting to ignore airspeed if it diverges too much from ground speed, I set this so that any large gusts disable the airspeed sensor making the plane control its speed much better by ignoring the gusts and maintaining its throttle rather than trying to regulate its airspeed going through the gusts.
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