화학공학소재연구정보센터
Automatica, Vol.48, No.5, 974-977, 2012
H-infinity design with fractional-order PD mu controllers
This article focuses on H-infinity performance design for fractional-order systems with time-delay, using fractional-order proportional-derivative (PD mu) controllers. First, the stabilizing parameters region in proportional-derivative plane of PD mu controller, for a fixed derivative-order, is determined in terms of a graphical stability criterion applicable to fractional-order time-delay systems. Then, in the stabilizing region, the pairs of proportional and derivative gains of PD mu controller are calculated for a range of frequencies, which satisfy the i-H-infinity-norm constraint of complementary sensitivity function and define the H-infinity boundary curve. Finally, by changing the derivative-order of PD mu controller, we observe the relationship between the H-infinity curve and the derivative-order. Examples are followed to illustrate the design procedure. 2012 Elsevier Ltd. All rights reserved.