Analysis and performance comparison of PID and fractional PI controllers

This paper compares the frequency domain performance criterion (Jv) of PI, fractional PI, and PID controllers when a step load disturbance is applied at the plant input. Process information is available in form of first-order plus dead-time (FOPDT) model. In addition, the controllers were compared using the H∞–norm of the sensitivity function as a measure of robustness, and some comments on industrial practice are offered in this context.