Log Analysis Help Flipping Drone

Hi,

I’ve been doing some flights for sometime with my quadcopter.
As soon as we take off, the drone starts rolling side to side, until it flips.

The last flight, we didn’t even put any controls in, only throttle. I’m attaching the log .bin file and any input would be greatly appreciated.

We looked into this ourselves and we did not see anything obvious or particularly bad, but I likely missed something.

https://www.mediafire.com/file/6t94dlhkujmeo4e/00000041.BIN/file

Did you configure the copter using the methodic configurator?
If you did then post the param files.

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Hi @WaveRep,

It looks like the copter hasn’t been tuned at all so that could certainly be the issue.

If it’s been flying fine and then suddenly stopped working then it’s likely a physical problem like a badly behaving ESC or motor. Maybe double check with MP’s Motor Test feature to make sure all the motors are connected correctly and spinning in the correct direction.

It also looks like ARMING_CHECK = 0 which is a bad sign. It’s probably best to change that parameter back to 1 and it’s possible that they may indicate what the issue is.

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Hi,

Unfortunately, we cannot fly it for long and after checking all ESCs and motors, everything is working properly.
Arming checks were set at 0, but after setting them to 1, we are running into the same behavior.
We used the methodic configurator to get the initial values for params and still seeing the same behavior - only always happens in roll.
After looking to the logs in more detail, we see that VibeY is slightly more noisy than others reaching values between 20 and 30, while the others are below 20. Also, we see a slight noise in the GyrY, leading to a small value of roll, followed by a massive reaction on motor output to correct.
This is then followed by a small time of stability and then this repeats, over and over, but with aggravated amplitudes.
We are planning to change accel and gyro filter values (away from the default 20 Hz) and reducing D gain and slightly P gain.
What do you think?
Thank you so much for all your input!
Cheers!

Hi @WaveRep,

this sounds like the Roll Rate gains are too low. So ATC_RAT_RLL_P, I, D. Normally setting I the same as P works so it’s really P and D that probably need to be raised. When manually tuning I normally keep the P to D ratio the same as the defaults and then raise both 10%, then 20%, etc until the vehicle becomes stable. Then sometimes I keep raising it until it becomes unstable. This gives a very basic tune that is at least flyable but not ideal