P.I.D. Tuning

[bgfireguy92]

OK so I've learned a lot already but I'm trying to tune the PID's to really dial in my Electrohub. So heres the stats:

Electrohub Spider Configuration with 9" Booms
RTF quads motor setup (T2212-980kv RTF motor, 20A Fire Red SimonK ESC, 9x4.5 Carbon Props)
Spektrum AR600 6 Channel Receiver
MultiWii Flip 1.5 "Pimped" with baro and mag flashed with MWC 2.3



Now here is my PID setup:



So now I started to follow what Bixler and Eric said and started turning the P up first little by little. I am fortunate being a firefighter that I could do this in the apparatus bays so no concerns of wind to throw me off. I turned up the pitch roll and yaw P settings together in incriments of .5 would write it and then test it to see if I hit that "oscillation" stage. I got to 8.5 and it was still steady as a rock, and I think even better responsiveness than the stock settings in the above pic. But then I started to worry cause I had gone so much already with no change and I read other forum threads on here of people tuning who got to 7 or 8 and theres was freaking out so i dialed it back to stock settings until I can hear from you wise and knowledgable people as to whats going on and help me formulate a plan to get this. So thanks in advance for any help. And I plan on trying to write an article after cause there are so many of us here who use the MWC Flip 1.5 so I know I cant be the only one struggling with this.

 

[meehan]

You are flying in "rate" mode correct? no self level? I always just crank up the P until I get obvious oscillation then back down a bit, with the P gain oscilations it will be harder to fly but flyable. One thing to note if you tune the P gain up inside or with zero wind you will likely need to knock it down a bit when the wind picks up. I would probably just go ahead and tune it outside.

 

[bgfireguy92]

Yes full on acro or rate mode, not auto leveling.

 

[jhitesma]

It should feel snappier and more responsive as you raise P. Then just when you really notice a difference and start to think "Yeah, just a little higher and it will be perfect" it suddenly hits the wall and you get oscillations. After that I usually end up having to go back a bit further.

I know a lot of people suggest using small changes when first tuning - but I admit I tend to go for fairly large jumps on MW .5-1 at first. But while still hand holding it with the props off - just to get a feel for where the limits are. Then I start making smaller adjustments actually flying.

I've had my knuckle quad on a similar setup only with 8" props on 1400kv motors in the 7's before hitting oscillations. When I ran the old wii gyros on it I actually had it up in the 9's. So I'm wondering if you have a filter setup overly restrictive or something.

And once you adjust the I and D the P may need to go back down quick sometimes. Increasing the I will give different oscillations but for me they're easier to spot than the P oscillations so if I think P is getting to high I'll work on I a little. Most of my setups started with a higher P than I ended up sticking with when just increasing P from the stock tune.

One other thing - the P is only noticeable if you move around. If you're just hovering you won't notice the response and may be raising it artificially high.. You want to tilt the vehicle back and forth to feel how it responds to fairly large movements.