Authors
Lee H Keel, Shankar P Bhattacharyya
Publication date
1997/8
Journal
IEEE transactions on automatic control
Volume
42
Issue
8
Pages
1098-1105
Publisher
IEEE
Description
We show by examples that optimum and robust controllers, designed by using the H/sub 2/, H/sub /spl infin//, l/sup 1/, and /spl mu/ formulations, can produce extremely fragile controllers, in the sense that vanishingly small perturbations of the coefficients of the designed controller destabilize the closed-loop control system. The examples show that this fragility usually manifests itself as extremely poor gain and phase margins of the closed-loop system. The calculations given here should raise a cautionary note and draw attention to the larger issue of controller sensitivity which may be important in other nonoptimal design techniques as well.
Total citations
Scholar articles
LH Keel, SP Bhattacharyya - IEEE transactions on automatic control, 1997