Analysis of interval system using model order reduction

Modeling physical systems usually results in complex high-order dynamic models. It is necessary to reduce it to a lower order system. A mixed method is suggested for reducing order of the large scale interval systems. Kharitonov polynomial is employed before the order reduction is come into the approximation process. The denominator polynomial of the reduced order is obtained by the improved pole clustering technique while numerator polynomial of reduced order is determined through the pade approximation method. The reduced order model so obtained preserves the stability of the higher order system. The proposed method is validated by numerical examples from the literature.