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PX4 / PX4-Autopilot

PX4 Autopilot Software
https://px4.io
BSD 3-Clause "New" or "Revised" License
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Unexpected flight termination #15289

Open kuiskas opened 4 years ago

kuiskas commented 4 years ago

Describe the bug We were flying a mission with our coaxial octocopter, v1.10.1. Suddenly the motors were stopped and the copter fell from 120m altitude. I have been looking the reason at the logs but did not found anything yet. Could any body help here. Could be a problem with the firmware?

To Reproduce Nothing special. In mission mode all the motors stopped and automatically from mission mode, freefall not detected, to position mode.

Log Files and Screenshots The logs are available here. https://review.px4.io/plot_app?log=44fcd17a-694d-431e-a02f-74c51f8d3cda

Drone (please complete the following information): Coaxial Octocopter, Pixhawk 4, Here+ 2.

Additional context We implemented some changes on the original v1.10.1. We are testing a dual redundant smart battery. Therefore we have changed the original smbus driver. Anyway the copter has been flying around some time with this battery, I really do not know what happened here.

bkueng commented 4 years ago

Sorry to read that. The vehicle did disarm in-flight, while still in mission (shortly before switching to position mode), but I do not see why. It's not RC, not landed and no vehicle command.

kuiskas commented 4 years ago

Hi @bkueng, thanks for your help. It saw in the logs, the vehicle enter in the maybe landed and landed condition but no frefall detected. I had several ideas but none of them could explain this.

  1. CPU overloaded, could this be? There is a peak just before everything happened.
  2. Could be vibrations?
kuiskas commented 4 years ago

Could be this? https://github.com/PX4/Firmware/issues/11683

MaEtUgR commented 4 years ago

Are all those CUV or apparently "undervoltage protection" warnings expected? It's first disarming, then detecting landed (probably because of zero thrust) image

MaEtUgR commented 4 years ago

Why is there no disarm message? 🤔 : image

MaEtUgR commented 4 years ago

@kuiskas Do your changes contain anything in commander and maybe arming_state_transition(... , vehicle_status_s::ARMING_STATE_STANDBY, ...); ? Just to rule it out.

kuiskas commented 4 years ago

Hi thank you all for you help here. here there is a log from 2 days before the crash, with the same setup: https://review.px4.io/plot_app?log=77a28b5c-f171-4f2c-8fc3-a98fa2beadf6 Later that day I flew a mission without problems. But I had the SD_LOG parameter set to from boot until disarm.

The CUV it is expected, it is a glitch in the smbus communication. It means cell undervoltage detected. From Commander we did not changed anything. Normally when landed and disarm we just get: imagen

kuiskas commented 4 years ago

Another thing we changed. The max number of task in nuttx. In our setup we were using 4 mavlink instances. USB instance + 3 for telemetry and peripherie. So we increased the max number of task to 64 as in the newer firmware. We did this because neither mavlink shell console nor the logger were working when this nunmber was 32 task. We had in total 33 task running.

kuiskas commented 4 years ago

Could the logger be wrong and the disarm occurred after the landing state? Any clue why is not detected a freefall?

stale[bot] commented 4 years ago

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