Need Help with Autotune on larger X8 Coxial Drone


I have a little problem using Autodrone on a larger drone, where I would need some help with:

We use the X-U8II with 80KV
31" Carbon folding propeller
Pixhawk Orange cube with 4.07 Firmware
The total weight of the drone is 7,5kg, + 4kg Payload and 7,7kg on batteries.

I uploaded a flight before autotune, the log during autotune and one short one after.

The drone did fly okay before, but still needed some tuning. I did fly autotune with very less wind, took in total 16-18min on all axes. I did than deactivated and activated autotune to fly the new PID´s and looked and felt good.

After landing I checked the new PID and already saw, that they are way to low, still made a short start but the drone was not stable at all.

So I´m not sure where the problem could be, never had this with any other drone of us during autotune. So I would really appriciate if someone could take a look at the logs.

Why are you flying on older firmware?
Your Flight after autotune is merely 10 seconds long :confused: Hard to judge based on that

Setup Harmonic Notch Filter and then try autotune for better results
You could also try running autotune multiple times with reduced aggressiveness but only after setting up notch filter (very essential)

What ESC’s are you using btw ?

I have a 960mm quad with Antigravity MN5006 NS18*6.0 props and AUW of 4kgs
I increased the scheduled loop rate to 800 which allowed me to lift the gyro filter a little bit more without introducing too much noise in motor outputs (Dont try this one if your not sure)

Thank you for the feedback.

We did fly it first with a newer firmware, but it did not fly great. So we went back to the 4.07 with same pids. But I have to say, this was a while ago with 4.10, we did not test 4.15 yet, but will do.

I checked the Noth Filter, you are right, it was not setup up, did this today.

For the ESC, we use here the coxial arm set from Tmotor, it has the Alpha ESCs built in.

The flight after autotune was for me not really flyable, so I landed after the 10 seconds.

If it’s flying well with the original pids, try to fine tune it manually, it’s not difficult and very good.