Support on Log analysis to understand a crash

Log Analysis -- deprecated Copter Logs -- deprecated
1

Hi there,

I hope some of you will be able to help me! I had an unexplained crash this weekend. My first flight on sunday was kinda perfect. But when i took off for the second one, my copter just went full throttle up after few seconds of flight (The copter climbed to around 100meter high). I was set in loiter mode. I didnt think about switching mode to stabilize mode to recover the control and i just switched off my RC which resulted in a crash…
I would really like to understand what happened in order to avoid another crash like this. But i’m quite nooby in log analysis. I’d really appreciate your help.
I join to my post the link of the logs of the flight:


Here is a link from the video of the flight… :

Thanks,
Nicolas

2

Hi Nico
if you plot CTUN.Alt and Baro.Alt you will see they differ.
the reason is that there were too much vibration on z accelerometer. so quad could not estimate its altitude correctly and acted crazily.
my suggestion is to improve your autopilot binding to the frame, check vibrations to be in the correct boundaries and start flying with stabilize mode.

3

Hello,
Thank You for your reply. What are the correct bouda ries for vibrations ?
By the way, What do You think about m’y battery voltage ? Is it normal That it drops from 16V to around 11.5 after the take off ?

4

your first question: http://ardupilot.org/copter/docs/common-diagnosing-problems-using-logs.html#vibrations
your second question: yes it is normal because when the amper increases, voltage should decrease.

how did you attach the autopilot to the frame? was it solid?

5

Yes obvously it was solid. I am planing to buy this :

is it good enough to prevent virabtions?

Moreover i will balance properly my propellers before a new test

6

Yes that anti vibrator can help. tell me what happened after installing it.

7

I will. Thank you for your help!

1 Like
8

I use them, they work nice