A mixed method for order reduction of interval systems

In this paper, systems having uncertain but bounded parameters are considered. An effective procedure to determine the reduced order model of system using mixed methods of eigen spectrum and Pade approximation is discussed. The eigen values of reduced order interval system are obtained using Eigen spectrum by preserving some of the characteristics such as centroid and stiffness of the original high order interval system. The numerator polynomial is obtained using Pade approximation by preserving some of the time moments and Markov parameters. It has been verified using numerical examples and compared with other method [14].