The ideal tuning setting for a PI controller is
- The integration time (Ki) is equal to the tau time of your proces.
If you don't set it like that you'll get overshoot you can compsensate for the overshoot a bit by increasing your proportional amplifier (Kp).
You can see this by adjusting the feedback cap over the bottom op amp (Ki) and the feedback resistor over the top op amp (Kp).
This only applies for a first order proces which we have here. The 1st order proces is the RC network. Yoy can try implementing a 2nd order proces by adding a second RC network in series.
