Title :
Discretization method of continuous-time controllers based on frequency response fitting
Author :
Chida, Yuichi ; Nishimura, Tomoaki
Author_Institution :
Dept. of Mech. Syst. Eng., Shinshu Univ., Nagano, Japan
Abstract :
In the present paper, a digital redesign problem that converts continuous-time controllers into digital controllers is considered. A new discretization method based on matching of the frequency response of a continuous-time control system is proposed. The frequency response is matched using the least squares method based on data of discrete frequency points. The matching problem is described using an LMI, and the stability condition of the closed-loop system and the redesigned controller are described as additional conditions of LMIs. An optimizing problem described by some LMI conditions is solved by an iterative procedure. Examples are presented that prove the superior performance of the proposed method.
Keywords :
closed loop systems; continuous time systems; discrete systems; frequency response; least mean squares methods; linear matrix inequalities; stability; LMI; closed-loop system; continuous-time controllers; digital controllers; digital redesign problem; discrete frequency points; discretization method; frequency response fitting; least squares method; matching problem; stability condition; Closed loop systems; Equations; Frequency control; Frequency response; Stability analysis; Transfer functions;
Conference_Titel :
Control Conference (ECC), 2007 European
Conference_Location :
Kos
Print_ISBN :
978-3-9524173-8-6
