Index of /skoge/publications/1987/Skogestad87a

[ICO]NameLast modifiedSizeDescription

[PARENTDIR]Parent Directory  -  
[TXT]README.html2010-07-15 10:06 1.7K 
[   ]Skogestad87a.pdf2010-07-15 10:06 1.7M 

Design of resilient processing plants-IX. Effect of model uncertainty on dynamic resilience
Sigurd Skogestad and Manfred Morari

Chemical Engineering Science
42 (7), 1987, pages 1765-1780

Abstract

The achievable quality of control for a particular system (its dynamic resilience) is limited by the nonminimum phase characteristics of the plant, constraints on the manipulated variables and model uncertainty. Model uncertainty requires that the controller be detuned and performance be sacrificed. The goal of this paper is to quantify this well-known qualitative statement. The closed-loop system must remain stable for all possible plants as defined by the uncertainty description. This robust stability requirement is used to derive simple bounds on the nominal performance for some specific cases. These bounds are relatively easy to evaluate and should be effective tools for screening alternative designs in terms of their resilience characteristics. The RGA and the minimized condition number are accurate measures with respect to element uncertainty, provided the relative errors of the transfer matrix elements are independent (uncorrelated) and have similar magnitude bounds.