Routh-Padé Approximants of two-dimensional separable-denominator continuous-time systems

A Routh-Padé approximation method to derive a two-dimensional (2-D) reduced-order model for a class of 2-D separable-denominator continuous-time system is presented. The proposed method preserves initial power-series-expansion-coefficients/Markov-parameters of the system as well as minimizes the errors of subsequent power-series-expansion-coefficients and/or Markov-parameters of the 2-D system and those of the model while preserving stability. VEGA is used for optimization.