MODEL REDUCTION IN TIME DOMAIN AND ITS APPLICATIONS

Abstract

The work included in this thesis deals with model reduction techniques in time-domain i.e. based on a state space equations of the original system. The first chapter introduces model reduction problem, its necessity and applications. Classification and critical review of model reduction techniques in time domain and frequency domain are given in chapter-2. Modal Analysis Approach and Optimal reduction techniques are discussed in detail in chapter-3. Applications of model order reduction are described in chapter-4. The respective step response of the illustrative examples taken from aircrft instrumentation systems are also shown for comparison purpose. A new low order model i.e. Marshall method with equivalent lag is introduced and when compared with the exact response, it is found to give an encouraging accuracy of prediction. A criterion for order selection of a reduced model is also given in chapter-5. The computer programs, in FORTRAN, for model reduction and step response, have also been developed and implemented successfully on a NEXUS-3000 Computer System.