Controller design via Pade approximation can lead to instability

Author

Silva, Guillermo J. ; Datta, Aniruddha ; Bhattacharyya, S.P.

Author_Institution

IBM Server Group, Austin, TX, USA

Volume

5

fYear

2001

fDate

2001

Firstpage

4733

Abstract

The Pade approximation is often used to approximate a pure time delay by a rational transfer function. In this paper, we show via examples that PID controllers that stabilize such an approximation may actually be destabilizing for the true system. Recent results, giving the entire set of stabilizing PID controllers for finite dimensional linear time invariant systems as well as for systems with time delay, are used to make a comparative study, through examples, of the stabilizing sets for the true plant and its Pade approximants

Keywords

approximation theory; closed loop systems; control system synthesis; delay systems; linear systems; multidimensional systems; process control; robust control; three-term control; transfer functions; PID controllers; Pade approximation; closed loop system; finite dimensional systems; linear time invariant systems; process control; rational transfer function; stabilization; time delay; Closed loop systems; Control systems; Delay effects; Feedback control; Pi control; Process control; Proportional control; Three-term control; Time invariant systems; Transfer functions;

fLanguage

English

Publisher

ieee

Conference_Titel

Decision and Control, 2001. Proceedings of the 40th IEEE Conference on

Conference_Location

Orlando, FL

Print_ISBN

0-7803-7061-9

Type

conf

DOI

10.1109/.2001.980953

Filename

980953