How does P gain+limit and I gain+limit work?

[loganj13]

I'm confused on how these work, and how adjusting them changes flight. Any chance you could explain how the individual esc  tuning works on the flightboard(specifically kk2.1.5)? thanks

[loganj13]

Above for individual esc tuning I meant mixer settings

[bigMouse]

Never found a true explanation of the Limits or how to use them! And never bothered to pursue it, so I tend to leave them at default!

The PID settings are complicated! I think I understand the theory but still have problems setting them up at times! Mainly because we all fly in a slightly different ways, and want the airframe tuned to how we as individuals fly!

On the KK2 your kind of lucky as the D term is either zero or fixed in firmware so if it exists, it's not a user adjustable variable (and there is nothing wrong with that!), leaving only P & I to adjust

P= Proportional is like raw gain! Think of it like a servo, The servo controller reads the position of the servo arm and compares it to the incoming pulse width, the difference is called the error signal, now if the cicuit was low gain, the arm would creep to the new position, attempting to reduce the error signal to zero, if the gain was too high it would energetically zoom to its new position, and overrun it constantly like oscillating at its new position. This is the P term, need to have it high but not so high that it oscillates!

I = Integral is Rate of change over a period of time, if it was controlling temperature it could have a variable name of degrees_change/secs etc. weird names but its only the value that counts, this is multiplied with the p term above, if it is large in comparison then the rate of change effect will be small, if it is the same then no change, small then a large change, some algorithms use the inverse (think multiWii does) secs/degrees so that a larger I makes a larger difference.(more comfortable for the brain) Some controllers use secs, some use mins, so the adjustable variable might be a large or very small number.

Summary is that the P term is proportional gain. I term affects the rate of change of P
Because I affects the operation of P. A change to I should be followed by a readjustment of P

I bet you wished you never asked now!

Try hovering, then rapidly move the roll stick left and right, if the quad climbs then reduce P!

KK2 boards more or less fly themselves on self leveling, on acro it really depends, I've had some easy to fly on acro, some just need full concentration to fly! Small quads usually need default P reducing.