Naze32 PID tuning QAV250 FAIL

[brdw]

I've recently built a QAV250 with a Naze32 Acro and Cleanflight. I have had several successful flights with the default settings but it doesn't feel particularly locked in and wind can easily push it around. I've calibrated the accelerometer/gyro and am running 1.9 firmware. I also lowered my P gain slightly because of high pitched oscillations on ascent.

After watching Flitetest's and other videos for PID tuning they all suggest doing P first, with I and D at zero. Some people then move on to I and D, or D and then I. I recently attempted to do this twice with different initial P settings and both times my quad was unable to take off and immediately went into a violent roll which destroyed my props.

So my question is what's a good starting place for P with I and D at 0?

I've also been tempted to take it up and try autotune but it seems like people have various luck with this, working for some and causing crashes for others.

 

[makattack]

Hi brdw! Welcome to the FTForums and sorry to hear you've been frustrated with the PID tuning. Yeah, you're not alone.

I'm no expert, but I do hope some of them will pipe up here. That said, I do know that if you're setting I and D to zero, with a 250 sized/mini quad, you will be making the P term the most significant control factor... which basically raises your P variable higher than before zero'ing I and D.

I assume you're using the default controller? (see https://github.com/cleanflight/cleanflight/blob/master/docs/PID tuning.md to find out more about the different controllers)

I don't know if it's the same... I don't use the default 0 controller, but I think the closest I use is PIDC 3 which is the "MultiWii23" and on my 250 sized quad, it flies nicely with Pitch set to (P,I,D) 33,8,8, roll 33,8,8 and Yaw 63,1,0 on 1.9.0 -- but YMMV...

 

[Snarls]

I personally would start with the stock values for your PID controller. They should at least get you flying. Instead of lowering I and D all the way to 0 I find it a lot easier to tune with just a little I and D, enough to keep the copter stable. I use like 0.10-0.15 I and 10-15 D to start with PID2 (Luxfloat). Violent roll after take off could mean your P gain is too high and oscillating out of control, or even too low and you are over correcting it. If you need help tuning all three P,I, and D let me know and I can link some helpful videos and threads.