i’m using arducopter 3.6.3 on large quad (800mm) and octo (1400mm) with 18" props/6S setups. After some weeks of troubleshooting i think i found a good pid setting, apart three things which i still cannot fix and didn’t find any effective solution:
too slow throttle response: it’s ok in stab mode but waaay too slow and smoothed out in alt-hold, loiter modes. Throttle has a big dead zone in the middle and long delay when you ask full or no throttle. Tried to work out the PILOT_SPEED_UP and _DN but it’s not enough since it changes the absolute speed but i have to tune dead zone in the middle and so…
abrupt roll/pitch attidude corrections: although stabilization is working well in general, it does it so abruptly fast, in terms that it’s simply SCARY, and despite my frames are very stiff, it seems they can break midair due to too much violent attitude corrections (especially in windy conditions or when doing full stick manouvers). That kind of stab output is ok for a FPV racer but a bigger drone needs a more gentle way.
Just to make an example (don’t get me wrong) DJI drones do the same corrections with a very gentle and smoothed angle acceleration, i would like to setup in that way. I only found a workaround to limit ANGLE_MAX to a low 2500 mdegs, but i would like to be able to set the corrections accel curves in a proper, smoothed way.
YAW pid: i can’t get a proper yaw in the Octo, command is very slow (which is acceptable) but it rebounces A LOT. I have quite high PIDs on it and getting higher does not affect it anymore.
I didn’t upload a log because i think it’s more a “feeling” issue than one to be analyzed by numbers, but if it can be useful i can upload one.
Thanks for help!