Design of Stable Controllers for Model Following Discrete Time Systems Using Approximate Inverse System.(Dept.M)

Abstract

A formulation of stable dynamical controllers is proposed for discrete time systems. Based on polynomial pole placement, the resulting controller may be unstable. Despite the fact that controller stability is often overlooked in the design strategy, it is of fundamental importance since the practical implementation of an unstable controller is extremely difficult. Using approximate inverse systems obtained from least square approximation, we show that unstable controllers can be avoided. One of the major points in this method is the use of least square approximation t determine an approximate inverse system easily, which is suitable for practical applications in control systems. The results of computer simulations are presented to illustrate the effectiveness of the proposed method.