Analytical design of discrete PI-PR controllers via dominant pole assignment.

In this study, a new discrete proportional integral-proportional retarded (D-PI-PR) controller design method is proposed. The proposed controller involves replacing the PD controller in the classical PI-PD control structure with a PR controller in discrete time and is implemented using dominant pole assignment, which is carried out by help of the modified Nyquist plot approach. The method starts with the determination of the controller parameters K and K in terms of the parameter K for a chosen delay parameter h after the computation of the desired dominant poles depending on the required closed-loop system performance criteria.