Pixhawk Suborbital Launch during Autotune

ArduCopter Copter 3.2
1

Hi there everyone! I have been dealing with some twitching issues with my pixhawk hex and found that previous autotune attempts on 3.2.1 have given me tuning results that tend to amplify rather than help twitching problems. It seems that ever time I run autotune, Roll/Pitch Sensitivity on the basic tuning tab gets maxed towards the end that makes it more twitchy. In order to start fresh, I loaded up default tuning parameters and went out for an autotune session. Partway through the autotune process, my hex decided to attempt a lunar orbit and took off. I was nervous so it took me a bit to get it flipped into stabilize, but I eventually got it brought back down. I am so far from a log expert that its not even funny, but did notice that I had a large z vibe spike but also had a ThrOut Spike to 100% that happened immediately rather than over time with vibration degradation. The thing that surprises me is that once things calmed down, the vibrations were well within spec. Nothing on the frame indicates any mechanical failure and all motors and props are well balanced. I have had this happen several times now and luckily it just goes up, rather than sideways.

My Hex:
Tarot 680 Frame
Pixhawk mounted on Kyosho Gel
Sunnysky 3508 580KV motors
RcTimer 1355 T Style Propellers
4S battery

Can anyone see anything in the attached log that may indicate something that needs to be addressed?
Also, Does anyone know why my autotune is yielding such aggressive tunes?

2

I am noticing that there is a fairly noticeable difference between IMU1 AccZ and IMU2 AccZ, most especially when the fly away occurs. Are these supposed to be closer than they are?

3

I was recently playing with this phenomena. I mounted the Pixhawk right to the base plate to see just what it does. Takeoff and basic fly around all looks good.

Now add a little wind and fly into it and wow. The copter will jump into the air and fill your shorts.

Your log looks like classic vibration issue. Either something moved while it was pitching back and forth or it started to fly into the wind.

I later fixed this issue by using a little foam to mount the Pixhawk. A world of difference you might say.

Mike