Copter fall during Autotune

Today was the first flight of my copter, and it was the tuning phase.

Autotune was completed with AUTOTUNE_AXES Pitch / Roll / YAW on the first flight and YAW also set YAWD on the second flight to complete tuning.

Greedy for the third flight, raised AUTOTUNE_AGGR to 0.12 (wind about 8m/s)
During the third Autotune, a photo-like message appeared and crashed.

Fortunately, the aircraft was not seriously damaged.
What happened to my drone?


Frame : Iflight Helion10 Pro

Motor : Axisflying 3215 730KV

Prop : Gemfan 1050

FC / ESC : Micoair743v2 / Bluejay 60A

GPS : Holybro Micro M10

Battery : 6S 6300mAh 70C Lipo

Which of these 3 logs show the issue we are supposed to focus on? All three show some rather strange things (most of which are self-induced), and all of them show AUTOTUNE_AGGR of 0.12, which doesn’t match your narrative above.

Why do you have arming checks disabled? This is likely adjacent to the root cause, as whatever arming checks fail could certainly cause issues.

You seem to be in a hurry to take off, and the initialization sequence is not complete before takeoff, which is certainly not helping.

Where did you see that AUTOTUNE_AGGR should ever be raised above 0.1? The documentation clearly states that the value should always be between 0.05 and 0.1. I know at least one developer who routinely reduces it to 0.08, but I know of no advice to increase it beyond 0.1.

Your last log shows that a crash_dump.bin file was produced, possibly as a result of a firmware panic after the physical crash you describe above.

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Looks like watchdog issues per the messages on the controller.

check the answers here by amilcarlucas

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How to methodically tune any ArduCopter | MethodicConfigurator

Autotuning in low-wind conditions is desirable, but if that is not possible you can increase the parameter value to 0.110 or even 0.120. That is a workaround and will not produce as good results as low-wind conditions autotune.AUTOTUNE_AGGR


I saw in the above post that if the wind is strong, the AUTOTUNE AGGR can be 0.11 or 0.12.
I may have misunderstood it because I check English through a translator.

The third flight log is the flight log at the time of the crash, but I don’t think the data was recorded accurately.

AUTOTUNE AGGR changed to 0.12 only on the third log flight, but I’m not sure why the rest of the log is also showing like that.

I will keep in mind that I will never turn off the arming check.

I’ve done autotune in quite significant wind and never increased the aggressiveness.
It was quite funny to see how well the copter coped with the wind gusts and it did a great job, funny because we’re so used to waiting for no wind or getting up early in the morning to do this.
The autotune result was valid and that tune is in use.
Thanks @Leonardthall

Battery voltage and current is all wrong - this will affect PID scaling.

I dont even see any motor outputs or ESC/RPM in that crash log.

Apart from the Arming Checks, also set these:

BATT_FS_CRT_ACT,1
BATT_FS_LOW_ACT,2

I don’t think the 3rd log (fall) has been saved since I plugged battery it in. Contrary to the log content, it actually flew, and it also crashed.
In the first and second logs, the voltage and current graphs seem to come out normally. ESC pwm and rpm as well.

I didn’t set up Battery Failsafe because I’m going to conduct this drone mainly on FPV ACRO flights.

I looked at the Autotune2 log and the voltage and the current do make sense this time - HOWEVER logging stops mid-flight as if the flight controller lost power so maybe the copter crashed then.
Check your connections, and maybe even see if the regulator on the flight controller is overheating or something. Leave it connected for a couple of hours and see how hot it gets, or if the FC loses power.

It’s important to set those battery failsafe actions regardless of “I know what I’m doing” and “I am just testing” - we’ve all been there and seen crashes exactly because the copter is disallowed from saving itself when your battery has a bad day.

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