| Title |
Design of the Zero Location for Minimizing the Peak Overshoot of Second-Order Discrete Systems |
| Authors |
이재석(Lee, Jae-Seok) ; 정태상(Chung Tae-Sang) |
| Keywords |
이차 이산 시스템 ; 단위계단 응답 ; 포락선 곡선 ; 최대 오버슈트 ; 감쇠비 ; 극점 ; 영점 ; |
| Abstract |
The damping ratio { xi} of the unit-step response of a second-order discrete system is a function of only the location of the closed-loop poles and is not directly related to the location of the system zero. However, the peak overshoot of the response is the function of both the damping ratio { xi} and an angle {α}, which is the phasor angle of the damped sinusoidal response and is determined by the relative location of the zero with respect to the closed-loop poles. Therefore, if the zero and the open-loop poles are relatively adjusted, through pole-zero cancellation, to maintain the desired (or designed) closed-loop poles, the damping ratio { xi} will also be maintained, while the angle {α} changes. Accordingly, when the closed-loop system poles are fixed, the peak overshoot is considered as a function of the angle {α} or the system zero location. In this paper the effects of the relative location of the zero on the system performance of a second-order discrete system is studied, and a design method of digital compensator which achieves a minimum peak overshoot while maintaining the desired system mode and the damping ratio of the unit step response is presented. |