# New Target Transfer Functions with No Overshoot

• Yang, Dae--Jeong (the School of Electrical & Electronics Engineering, Chungbuk National University, 48 Gaeshin-dong, Cheongju 361-763, Korea.) ;
• Kim, Young-Chol (the School of Electrical & Electronics Engineering, Chungbuk National University, 48 Gaeshin-dong, Cheongju 361-763, Korea.)
• Published : 2001.03.01

#### Abstract

To design a controller based on the pole placement method, it is necessary to obtain either a target transfer function or a desired characteristic equation which results in the closed-loop response. Specially, a step response in which no overshoot occurs in highly desirable in many applications. In this paper, we present two new present two new prototypes of Type I target transfer functions whose step responses have an overshoot of less than 0.1%. One prototype is obtained by Taylor's approximation of a Gaussian function. It is, however, observed that the response delays increase with increasing order, while the rise times are nearly constant. The other prototype is a modification of the first prototype, so that their transfer function coefficients have particular values in terms of specific parameters ${\gamma}$i and $\tau$ (see section 2). The second prototype gives very useful properties in which step responses are almost the same shape, irrespective of the order. It, also, has no overshoot. Some other properties of the prototypes and an application example are given.