MODEL REDUCTION OF DISCRETE TIME SYSTEMS AND ITS APPLICATION IN CONTROL SYSTEM DESIGN

Abstract

In recent years there has been a rapid increase in the use of digital computers in control systems. In fact, many industrial control systems include digital computers as an integral part of their operation . Digital controls are used for achieving optimal performance- for example, in the form of maximum productivity , maximum profit., minimum cost or minimum energy case. Also , the availability of low cost microprocessors and microcomputers, which can be used for various control functions has established a new trend towards the inclusion of digital computers even in small-scale:'. control systems to obtain optimal performance."?'.' The current trend towards digital control rather than,'.,. analog control of dynamic systems is mainly -du.e to the availability,of low cost digital computers and the advantages found in working with digital signal rather than continuous time signal. In control engineering , digital computers have been used for two different purposes. First, they have been used for the analysis and synthesis of complex control systems, including digital simulation and digital computation of complex control dynamics. Second , they have been included in control systems as controllers. In the present dissertation Model Reduction Technique and designing of Digital Controller and their performance analysis have been discussed The method discussed is a simple and computationally efficient. Efficient computer programmes have been developed in FORTRAN for carrying out the computational work Tire outline of the dissertation is as follows Chapter I.,gives a brief introduction of model reduction and reasons in going for lower order models and need of digital controllers. Chapter 2 presents the statement of model order reduction problem and review Chapter 3 deals with 1:I3€' necessary mathematical preliminaries Chapter 4 presents proposed model order reduction method Chapter 5 discusses design method of digital controller and Chapter 6 discusses conclusion , analysis and scope for future work.