Montazeri A., Esmaeil Sabzali H., Poshtan J., Jahed Motlagh M.

This paper aims to present a suitable model of a flexible beam and its associated uncertainties in order to be utilized by robust control techniques such as . This model then can be used for active vibration control of a beam. Fundamentally, analytic models of lightly damped flexible structures such as beam are infinite dimensional. In order to design a controller for this structure one has to have a finite dimensional model. This model truncation often leads to poor performance and stability. To overcome this problem, robust controllers are introduced. Therefore specific identification methods are necessary when one seeks to use robust control schemes. Identification methods producing a nominal model and its associated uncertainty are known as ‘Robust Identification’ or ‘Control-oriented Identification’ methods. In particular, our approach is ‘Set Membership’. This method is based on deterministic hypothesis about uncertainties. In other words, in this approach, uncertainties including measurement noise and high frequency unmodeled dynamics are assumed to be ‘Unknown but Bounded’ (UBB). In this paper, the considered algorithm, estimates the set of nominal model parameters compatible with input-output data and a priori system’s information with an ‘Ellipsoid’ in the space of nominal model parameters. In order to for uncertainty computed by the proposed algorithm can be handled by nonparametric robust controller design techniques, it has to be presented in frequency domain.