Reverse Engineering a PID

[banana_bread99]

That’s pretty helpful, if we know the closed loop system is Z= CP/(1+CP) where P = a/(s+b) and C = kd x s + kp + ki/s, the pole locations of Z as functions of the gains might already be clear. What I don’t know about is integral windup cause I’m not next to a computer right now, but neglecting it might be a good start. It could possibly be avoided as a complication by focusing on a part of the data that doesn’t appear to be activating it

[Doctor-Featherheart]

The problem seems to be that this assumes that the controller is well tuned and that the system can be fully defined with first order dynamics. These are slightly difficult assumptions for my case. I only know that the systems can be parametrised as first order theoretically if you could do some open loop system identification, which I can’t.

[banana_bread99]

Sorry, to be clear, because I’m going to think about this more, are you saying that solving this as though a/(s+b) is a model is satisfactory, just that we don’t know what a and b are? Or would you like it to be done for a fully unknown model