Biased model reduction by simplified Routh approximation method

Model reduction by the simplified Routh approximation method (SRAM) is extended to produce biased models. The method uses only one Routh-type array to generate both numerator and denominator of the kth-order model. Computation of the time moments and Markov parameters of the retained system beforehand and solving the Padé equation for the reduced numerator are not necessary. Numerical examples illustrate the method.