Tarot X4 - First Flight - I need some hints related to PID tuning

🧪 Flight Testing & Log Analysis
1

Hello,

I have built a Tarot X4 drone. I used the default PID settings. The first flight was “successful” but not really good. I think the PID parameter should be changed. I read the PX4 documentation but the current Logfile: https://review.px4.io/plot_app?log=f01077f1-ca6f-480d-929f-e678c2d8fc68
shows some diagrams ( PID Analysis ) which are not described in Influence of parameters · Plasmatree/PID-Analyzer Wiki · GitHub.

It would be nice to get a hint, what I have to do with K, D and I parameter.

My LogFile: https://review.px4.io/plot_app?log=f01077f1-ca6f-480d-929f-e678c2d8fc68

Should I increment the K parameter if Step Response line is permanently below the 1.0 ?
Should I decrement the K parameter if Step Response line is permanently above the 1.0 ?
What I have to do with the D Parameter ?

Thank you in advance

Best regards

Andreas

2

Hello @abaumann,

Just as a suggestion for the best performance, I would look into mitigating the vibration going into your PX4 first (typically, large folding airframes give you lots of vibration due to poor structural design). From my experience, I never had any luck with reducing vibration with one of those Pixhawk mounts with blue rubber joints. O-ring suspension mount is what I have found to be the best at minimizing low frequency vibration inherent in large airframes.

This is a good documentation on the subject. Once you have a good base performance out of your vehicle, this would be a good starting point for PID tuning.

Also, try looking into default airframes that’s closer to the size of your airframe. Maybe you could get hints from their default parameters which are really well tuned for most purposes.