Design of PI controllers for achieving time and frequency domain specifications simultaneously

This paper deals with the design of PI controllers which achieve the desired frequency and time domain specifications simultaneously. A systematic method, which is effective and simple to apply, is proposed. The required values of the frequency domain performance measures namely the gain and phase margins and the time domain performance measures such as settling time and overshoot are defined prior to the design. Then, to meet these desired performance values, a method which presents a graphical relation between the required performance values and the parameters of the PI controller is given. Thus, a set of PI controllers which attain desired performances can be found using the graphical relations. Illustrative examples are given to demonstrate the benefits of the method presented.