Order Reduction Techniques via Routh Approximation: A Critical Survey

Routh Approximation is believed to witness tremendous usage in deriving the reduced models from their higher equivalents. Order reduction is a critical field of interest for researchers or control engineers dealing with practical and physical systems of higher order. Reason for the popularity of Routh Approximation among other reduction methodologies is its strength of computational simplicity, ease of access and the promise to retain the model stability. This paper accomplishes a survey of the available Routh Approximation algorithms in their varied configuration since five decades. Last survey report based on Routh Approximation was cited in late seventies as discussed in the paper. One prime reason for the outcome of this paper is the problem met by the authors during their own work for analysing varied configuration of Routh Approximation for order reduction. Many times, the arrangement, stated or performed, seemed to be already in existence. Thus, the paper would be helpful to the researchers working in the area of order reduction and have prime focus on the utility of Routh Approximation.