Hamid Safikhani - Islamic Azad University of Khomeini shahr, Esfahan, Iran

In many industrial process, reaching a transient response without overshoot is important. Therefore, design of controller for having optimal transient response and without overshoot is considered. In this thesis, PID controller is designed that first, the closed-loop system stability is guaranteed and second, step response of the closed-loop system has not overshoot. For having non-overshoot in step response of system, controller coefficients are calculated that measure of closed-loop frequency response of the system is strictly descending. Strictly descending of frequency response means that having transient response without overshoot or having a minimum overshoot in transient response. Thus, we find a region in PID controller parameters that in the region, transient response of close loop system is stable and has not overshoot. Obviously, in the region we can select infinite variety controller. Simulation results on numerical examples show the effectiveness of the proposed method.

Fractional-order PID controller, transient response control, non-overshooting step response