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PX4 / PX4-Autopilot

PX4 Autopilot Software
https://px4.io
BSD 3-Clause "New" or "Revised" License
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Achievable speed against heavy wind depends on auto vs manual #11646

Closed MaEtUgR closed 4 years ago

MaEtUgR commented 5 years ago

Describe the bug I cannot be 100% sure that this also happens on master but I'm assuming this now and verify.

To Reproduce Steps to reproduce the behavior:

  1. Set the mission cruise speed and the manual position full stick flight speed to the same relatively high value e.g. 10m/s
  2. Fly away from you in very heavy wind
  3. Fly back to you in manual position mode full speed against the wind Setpoint is full speed but you don't reach full speed because of the wind
  4. Switch to RTL which should continue flight with the cruise speed (you configured it to be the same) Setpoint stays the same and now you reach it

I repeated this several times and verified it's not the wind changing drastically in between the two modes.

Expected behavior You can reach the same speed in both modes even against the wind if the vehicle has enough power (which it clearly had in my case).

Log Files and Screenshots https://logs.px4.io/plot_app?log=f8817dcc-abda-466a-b223-9e504e3486fd

log_bug

Drone: Yuneec H520

Additional context

Any help or even hint is appreciated, otherwise I'll try to solve it myself.

stale[bot] commented 5 years ago

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

stale[bot] commented 5 years ago

Closing as stale.

stale[bot] commented 5 years ago

This issue has been automatically marked as stale because it has not had recent activity. Thank you for your contributions.

MaEtUgR commented 4 years ago

I just checked the log again and apparently I was wrong in:

  • Both times it's a velocity setpoint that should be reached and it's not a feed-forward to position control.

There is a position setpoint moving with the drone when doing RTL and that seems to be why it reaches the correct velocity. So this is not really a strange bug but a possible side effect given these setpoints and the vehicle tuning e.g. horizontal velocity integral.

plot not reach velocity