Drone Flipped Over When Initial Flying Status

[selina]

Dear Modal AI Engineers,

I am now working on the RB5 drone in both manual mode (RC controller) and offboard mode. Now, I can arm the drone successfully in both ways.

I installed the propellers and the drone flipped over when I 1) used the manual controller to make it fly upward and 2) used the setpoint_position for sending target point in OFFBOARD mode in mavros with MOCAP.

I wish to check the problems and for safety reason, I didn't install the propellers now. I check the QGroundControl and the mavros topic for esc_status, and I noticed that motor 1,3,4 could maintain at 7000+ rpm for flying upward but the motor 2 will first grow to 7000+ and then finally fall to 2000+ rpm. The current of motor 2 is about a quarter of the others. However, motor 2 could present similar performance when testing it separately via QGC.

I wonder if there is anything else I did not notice.

Thanks for your support!

Best wishes,
Selina

[Alex Kushleyev]

Hello @selina,

Do you have any px4 logs from the original flight(s) which exhibited the flipping behavior? The logs contain the commanded and actual RPM (as well as many other things) and we can check what happened.

If you don't have any sensitive information (gps location that you dont want to share, etc), you could upload the log to https://review.px4.io/ and that will give you some information and we will be able to grab that log and further analyze it to parse the custom ESC messages that standard px4 flight review does not support.

Alex