The initial tune flight oscillates in roll and pitch as shown in graph.
After reducing 50% of PIDs for roll & pitch rate as described in Initial Aircraft tune, the error is getting worse as in below graph. Please advice.
I don’t believe its getting worse, It seems to be getting better? The closer the DesRoll/DesPitch is to the Roll/Pitch the better, Keep repeating the process until you get a stable tune.
Also If you’d like to request advice then please attach a log to the post.
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Thanks! I’ll repeat the process. I thought that it’s overshooting and desired roll grows, not knowing why, I’m just hovering it without roll/pitch input. When landing, it topples just before the ground.
Big expensive and dangerous copters lile that need a methodic and systematic tuning.
It would be great if a specialy designed ArduPilot configuration
software would semi automate that process, helping the users to get it right on the first attempt 
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lucus,
the tuning is not getting worse, the actual roll more closely follows the desired one than the first attempt. The PID tuning of these large drones is not an easy task, it usually requires more than one tuning sessions to get it right. At first you have to set PIDs that are somewhat acceptable for your craft (meaning it won’t crash at first flight), then work on from there. You can make several PID autotune sessions, only making the aircraft do any of the pitch/roll/yaw directions one at a time and then writing the values onto the flight controller and continuing from then onwards.
Make sure that the drone does not have any excessive weight imbalances or overhangs that might influence the tuning process! This means that center of weight must be close to the central vertical axis of the flight controller, and can be lower than the controller’s main horizontal plane, but having larger mass higher than it can have adverse effects!
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