MODEL SIMPLIFICATION OF LINEAR DYNAMIC SYSTEMS BY CONTINUED FRACTION EXPANSION TECHNIQUE.

It is often desirable and sometimes necessary to reduce the order of linear dynamic systems in the analysis and design of control systems. Several methods are available to reduce the dimensionality of the system. Among the various methods, the one due to C. Chen and L. Sheih is considered most powerful and requires less computational time. In their technique of model simplification the given higher order transfer function is expanded into continued fraction expansion and some of the quotients are ignored depending upon the order of the required model. A systematic justification for this procedure via sensitivity considerations is provided in this paper. This approach indicates that the simplification is applicable to control systems which can normally be considered as low pass filters.