Quadcopter crashed in altitude mode - Pixhawk

Flight Testing & Log Analysis
1

Hi,

I have built an F-450 frame based quadcopter with pixhawk.

Flight Logs - 1:18mins

Here it goes -
[Actions]

  1. Armed it.
  2. Lifted it off in Stabilize mode.
  3. After a certain height - i put it into altitude mode.
  4. Drone maintains height as i am only controlling roll and pitch.

[Observations]
5. Sometimes when i use roll and pitch to navigate the drone, i see altitude dropping abit (no crash).
6. While still being in altitude mode, i suddenly see - one of the ESCs (zip tied with arm) got fried and caught fire. Shortly after it, Drone nosedived and crashed into ground.

[Actions]
7. Tried disarming upon crash. (Throttle to bottom and then left).

What i want to understand ?

  1. I have been going through logs but unfortunately cannot understand why did it crash. I am still new to drones, cannot interpret the results well.
  2. Similar thing (crash) happened two days ago. it was in altitude mode for 40seconds. And then suddenly flipped and came to ground, then flew again to the same altitude. and then crashed to ground.
    (Flying → Flipped and crashed to ground (fortunately on legs) → flew again to same altitude → then finally crashed after 1 second) .. later i got to know that PDB board had gone fried, wasnt supplying voltage. Unfortunately, don’t have logs for this flight :frowning:

But seeing these two flight fail was very similar. This time i have captured logs, Can anyone please help make sense out of it?

2

Sounds to me like something is wrong with the ESCs then. Are they rated high enough in terms of current?

1 Like
3

Thank you for the response. I digged into a bit,

ESCs - Standard 30Amps ESC Rated for 3S max.

I am using 4S battery. The ESC was rated for 3S - at 30 Amps. Another thing, i realized my motors are rated for high peak current.

Maybe, this is the issue?

I have ordered another ESC, which has burst for 60Amps and constant current 40amps.

One thing while reviewing the logs, i am worried about is that “Vibration Metrics” and “Power Spectral Density” charts. Do you think, there is something wrong with my frame?

4

I suggest to have a read through this: Vibration Isolation | PX4 Guide (main)