Sensitivity reduced design of discrete linear regulator with prescribed degree of stability

Abstract

A method is proposed for the design of constant-gain feedback control laws which reduce trajectory sensitivity to small system parameter variations and ensure the prescribed degree of stability for discrete-time systems. The selected performance index is of standard linear regulator type; modified to include a quadratic sensitivity term and weighting function (α)2k with α > 1, which ensures that the closed-loop poles will lie inside the circle of radius 1/α in the complex plane. An example of a two-area load frequency control system is presented to illustrate the application of the design procedure.