Balanced tuning of PI controllers

This paper proposes that PI controllers should be tuned with balanced proportional and integral actions. The tuning method involves the achievement of a critically damped control loop and/or the minimization of an extended Integral-Time-Absolute-Error (ITAE) criterion. As shown by simulation results on a batch of test processes, balanced tuning provides a robust control loop with good gain margin and smooth responses with almost no overshoot. The tuning method is model-free aud can be used in an iterative closed-loop procedure.