How to Tune PIDs
Okay so we have done the first step of the process of getting up in the air and flying your quad, which is the first step. The second step in order to get into the air is to have a good tuned quad that responds to your commands on the sticks. That is where tuning your PIDs play a huge role on making that happened. But before getting started with anything you want to know what each of the variables do in order to get a good tune.
P (Proportional)– this is the most important variable and the one you want to take your time on while tuning because this will dictate how locked in and responsive your quad feels.
I (Integral)- the integral is also an important variable to tune, just not as important as the p, since your quad could actually fly with very low I and D. Your integral is responsible for keeping your quad at the same angle while forward, backwards and side to side flight.
D (Derivative)- The D term is what I like to call the small details/ fine adjustments to your tune. The derivative dictates very small oscillations and bounce back during harsh 180 degree turns, flips and turns. Having D too high can also cause minor oscillations so keep that in mind when tuning for D.
ALWAYS TUNE WITH FRESH PROPS & FRESH BATTERY AS YOU WANT TO HAVE HIGH VOLTAGE BECAUSE LOWER VOLTAGE MAY NOT SHOW THE OSCILLATIONS FROM P TERM THE SAME AS HIGHER VOLTAGE WOULD.
How to Tune P(Proportional)
So now that you know or at least have an idea of what each variable in PIDs does we can begin tuning the quad. First you will want to begin tuning with P then I then D.
With P you want to raise it by increments of at least 3-6 until you begin to experience oscillation at hover or at full throttle punch outs. Listen to oscillations at hover since later we can use TPA to get rid of oscillations at full throttle. This will function to give you a good P value for the pitch axis. Another good way is to split S over trees and if it oscillates then your P is to high and you want to slightly bring it down about 1-3 points. For the roll axis one thing I found that helps me out figuring out a good value is to stay on throttle during nice course maneuvers/ turns. What I mean by that is do nice wide turns and stay on the throttle, if you are experiencing oscillations bring the P down just a tad bit.
By raising P this is allowing the quad to get a very snappy and responsive feel, which will also feel like if the quad just goes where you want it to go. So this is why you want to take your time while tuning P and getting the best possible value for your P term because you want the quad to feel responsive.
After you have found the value that feels best for you and is not giving you much oscillations you could begin to add at least .10 – .20 to your TPA to help get rid of those oscillations at high throttle. By adding TPA you will not have to lower the P and sacrifice the feel and responsiveness of your quad.
How to Tune I (Integral)
So for your I you want to make some split S maneuvers and stay on throttle to see how well it hold that angle, if it doesn’t hold the angle that well you will want to begin raising (I) that way it can stop doing this and feel more locked in during these maneuvers, this is only for the pitch axis.
For the roll axis you will want hover the quad and angle over left or right and leave the quad going that direction with about that 45 degree angle and depending how well stock pids are it should stay locked in to the 45 degrees if it doesn’t remain that angle then you’ll need to raise I. You could also do this for your pitch axis, if your (I) is too high the quad will get slight oscillations and will get you confused for oscillations from P but know that usually raising the I about 12-15 points from stock is usually gives it a very well rounded locked in quad.
How to Tune D (Derivative)
Last but not least let’s figure out the small details to make this quad fly like a champ! The D term is very easy to tune. First go ahead and test for how well the stock D values fly and look for bounce back during flips and rolls. If there is bounce back during rolls then raise the D on the roll axis and if there is bounce back during flips then raise the D on the pitch axis.
As far as racing goes since we don’t use Pitch as much as we do roll the D term value will be lower than your roll. Another way to tune for D is to do harsh 180 degree turns at full throttle and if you are getting what we call prop wash (bounce back/osicllations) then bring D up on the roll axis until you remove that prop wash about 85% this prop wash will not be 100% gone but you can get very close to it by raising the D on the roll axis.
When is it enough D? Well you know your D is too high when you start gaining oscillations after you have already tuned P and I. Keep in mind that if your D is too high then you’ll start to feel that the quad starts getting very mushy and sloppy feeling to it and will pretty much start taking the snappy feel that you first tuned for from the P. So don’t get too hung up on getting the prop wash completely out, because if you keep raising the D you’ll sacrifice the feel from the P.
YOU SHOULD NOW BE DONE TUNING YOUR QUAD!!!!!