Robust Identification with Mixed time/frequencydomain experiments: Theory and an Application

MARIO SZNAIER; TAMER INANC; RICARDO S. SÁNCHEZ PEÑA; PABLO PARRILO

Albuquerque

Conferencia; American Control Conference; 1997

American Automatic Control Council

We have recently proposed a new robust identificationframework, based upon generalised interpolation theory, thatallows for combining both frequency and time-domain experimentaldata. In this paper we apply this framework to theproblem of identifying a two-degree of freedom structure usedas a testbed for demonstrating damagemitigation and life extensioncontrol concepts. This structure is poorly damped,leading to time and frequency domain responses that exhibitlarge peaks, thus rendering the identification problem nontrivial.The main advantage of the method, avoiding situationswhere good fitting in one domain is obtained at the expenseof poor fitting in the other, is illustrated by comparing the resultsagainst those obtained using more classical pure !' andX,, methods.