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PX4 / PX4-Autopilot

PX4 Autopilot Software
https://px4.io
BSD 3-Clause "New" or "Revised" License
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v1.11 beta VTOL standard issues (needs review) #15138

Closed dagar closed 3 years ago

dagar commented 4 years ago

Logs

  1. https://logs.px4.io/plot_app?log=fc8a7b1e-24ec-4200-abe4-e76dc959047d
    • log001_4_RC_test.ulg
    • we tested RC commands
  2. https://logs.px4.io/plot_app?log=252166fd-5e22-4879-b8f5-9a0a053da57e
    • log001_5_bad_takeoff_and_land.ulg
    • during take off VTOL was blown away because of the wind but he still manage to start mission, in vtol land he was also blown away and fall down on different location
  3. https://logs.px4.io/plot_app?log=d1f696a9-e622-4d11-9821-64a80efa86ef
    • log001_7_takeoff_failed.ulg
    • VTOL was blown away on take off, far far far away and he didn't start the mission, before touching the ground we tryed to save him with RC... when I came to him I saw that he was still running engings (he didn't disarm in the grass)
saengphet commented 4 years ago

Hi, @dagar I saw something in Actuator output (MAIN) graph, motor 1 and 2 (CCW), and motor 3 and 4 (CW) look significantly separated. Are motors well alignment? or it is just the wind effect cause CW and CCW motor run differently (diff. more than 300 PWM is so weird for me).

dagar commented 4 years ago

These are logs from @MartinStokelj shared on slack I'm trying to capture in one place for review. Anything else about the vehicle you can share with us @MartinStokelj?

If you have previous good logs from the same vehicle it never hurts to upload (http://logs.px4.io) and share them for comparison.

MartinStokelj commented 4 years ago

I hope this will be helpful. VTOL - TC off https://review.px4.io/plot_app?log=dc294a34-934c-443e-9f53-6a48223caa13 https://review.px4.io/plot_app?log=3bcfc630-9f5c-45ea-9997-0507c56a970f https://review.px4.io/plot_app?log=7f13c35d-e9b5-4f88-973d-52574b7016cf https://review.px4.io/plot_app?log=e74da84c-f2e0-406a-91ee-20e1e04f231d https://review.px4.io/plot_app?log=d96cd3c2-68d3-42ce-b166-3f2d74b42f30 VTOL- TC on, NO wind https://review.px4.io/plot_app?log=6397d2ce-11c2-455b-8d35-fff7454aac02 https://review.px4.io/plot_app?log=572e03dd-645b-44df-abfd-038a41428f2d (failed to takeoff) VTOL - TC on, wind, Weathervane bug on master https://review.px4.io/plot_app?log=ed8bcc5a-08f8-4329-bb53-1f3a40f3fa03 (failed to takeoff) https://review.px4.io/plot_app?log=26c014eb-74bb-46d9-9ffb-908480294b50 (failed to takeoff) https://review.px4.io/plot_app?log=b858d7d3-c0ea-4e76-bed5-b301ada47f98 (failed to takeoff) https://review.px4.io/plot_app?log=3ffcdc77-0c76-4d73-8c33-758e31ce1938 https://review.px4.io/plot_app?log=19913b92-33c1-410c-a030-bcf97dc9762c

https://review.px4.io/plot_app?log=24797ba1-2a7f-437a-ac5a-fc40bec0d4e8 https://review.px4.io/plot_app?log=2d2fb371-a815-4ce9-af8b-94d0db90b258 (failed to takeoff) https://review.px4.io/plot_app?log=33288158-d40f-4e86-92e8-02d4440b576f (failed to takeoff) https://review.px4.io/plot_app?log=596ca957-de8d-4026-9cf2-5f2bd45f51cc (failed to takeoff) https://review.px4.io/plot_app?log=482d3f38-ca3c-4f0e-a209-e4cc0636e870 (failed to takeoff)

MartinStokelj commented 4 years ago

Perhaps it would be good to check parameters. Allowing yaw in vtol takeoff? param_VTOL.zip

sfuhrer commented 4 years ago

@MartinStokelj are you using a DeltaQuad or a custom airframe? I think the hover thrust margin is really low, the vehicle needs about 80% to fly level, right? Or the other way round, the vehicle sometimes barely climbs when full on throttle. image I personally haven't seen a VTOL fly well that had a hover thrust above 60%, as on a VTOL (especially in wind) the MC motors have to fight quite a bit against the aerodynamic forces and moments generated by the body.

MartinStokelj commented 4 years ago

@sfuhrer we are using DeltaQuad. So what do you suggest?

MartinStokelj commented 4 years ago

We increased the propellers and make new flights. Wind was low today. RC test https://review.px4.io/plot_app?log=37caf131-19a8-42db-b9fb-bc06677de3c6 2x flight (great VTOL take off, bad VTOL land, transition was very fast and far away from landing point (probably we need to update some parameters because of bigger propellers)) https://review.px4.io/plot_app?log=9bcf5d46-7479-4841-9049-f2f2e1c330dd https://review.px4.io/plot_app?log=d6a593c1-a715-41c4-8a99-7a68cf4b7045 Crash (transition timeout has forced him to go 100agl then we lose control in manual mode (probably one propeller fall off since VTOL start to spinning around (yaw))) https://review.px4.io/plot_app?log=2a8bea0b-7148-4202-a516-e5cdc8b8b165

sfuhrer commented 4 years ago

@MartinStokelj sorry to hear about the crash. Hope it's not too bad. You can increase the VTOL transition timeout via VT_TRANS_TIMEOUT, but actually it's pretty bad if the vehicle can't accelerate within 15s to cruise airspeed, so I would also there consider upgrading your motor/propeller. Let me know if I can help you with anything else specifically.

MartinStokelj commented 4 years ago

Today we had wind and went flying again. We actually made only 1 flight but even that one had problem in transition.

no global position on VTOL take off, VTOL has landed, I beleave he even shut down motors in air. https://review.px4.io/plot_app?log=16c22dbe-c8da-4e5f-842f-8e364b6215af https://review.px4.io/plot_app?log=9f74123d-2118-499b-a463-37d90c9f8b5c We did calibrations again. Actual flight (AMSL problem when doing transition to fixed wing, Fused altitude is way off but only in transition time, we saw negative AMSL and AGL in QgroundControl) https://review.px4.io/plot_app?log=8b63304d-c5b3-4941-bc83-26b0f316a69d VTOL Takeoff (AMSL problem when doing transition to fixed wing, Fused altitude is way off all the time of the flight) https://review.px4.io/plot_app?log=e0dc1e82-3ef9-44fb-a2e1-5f0ebd09a3fe https://review.px4.io/plot_app?log=df746d69-510e-4d19-8167-e63442185bf5

I think weathervane worked great, drone was facing the wind and he made corrections with main propeller.

MartinStokelj commented 4 years ago

@ThomasRigi commented on slack "I think the increased vibrations during transitions throw off your accelerometer sensors"

Since last crash we gave same size propellers but they are very soft, we will buy the previous ones again if this is doing the vibrations. We also ordered more stronger motor as @sfuhrer suggested. I am a bit shocked that vibrations can affect the calculated altitude. PX4 should detect that fused altitude is way off from GPS and Barometer altitude.

stale[bot] commented 3 years ago

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

LorenzMeier commented 3 years ago

I'm closing this issue as stale - @MartinStokelj on your comment on altitude: The hard part in system engineering is to detect failure and to not detect a "sane" system as faulty at the same time. Post-flight that's easy, but building a reliable algorithm is an art. A decade of work has gone into the state estimation framework and it is extremely robust for reasonable setups (and it is deployed in tens of thousands of products) - but there are limits to everything.