Indoor, optical flow px4 for horizontal position, barometer for alt

copter v 3.6.7

here is tel log
2020-03-05 11-02-34.tlog (499.6 KB)

I found optical flow was not working, then drone was going to ceiling

then crush.

in manual of optical flow px4, it doesn’t work without proper sonar

I think that is the problem.

If there are other problems, please reply

Thank you for your time

You should update your Firmware to Copter-4.0.3. It allows optical flow pointing down and/or optical flow pointing up. Both need proper sonar!!!

Thank you for your advice. I will do it