Abstract
In this paper the authors have revealed the relations between the transient and steady-state characteristics of the zero non-regular control systems with a zero in the right-half root plane, and the pole-zero configurations of the closed-loop transfer functions in the root plane, and considered on the determination of the closed-loop transfer functions satisfying some specifications. The summarized conclusions are as follows.
1. If the location of the zero in the right-half plane is nearer to the origin than those of the poles in the left-half plane, the indicial response of the system exhibits the large undershoot and the large overshoot.
2. Because of the existence of the undershoot the minimum value of the integral of squared error (ISE) of the system is obtained for non-oscillatory one.
3. The presence of the zero located near the origin on the real axis in the left-half plane, which makes both the undershoot and the overshoot larger, renders the rise time shorter and reduces the steady-state velocity error. Thus the system designer is forced to choose the pole-zero configuration by a compromise between the steady state velocity error and the undershoot (or the overshoot to design type-I servomechanism.
