On the estimating errors and the structures of identity observers and minimal order state observers

Abstract

Bongiorno and Youla showed that the increase in the performance of an optimal regulator incorporating an observer sometimes tends to infinity when all the poles of the observer are assigned negative infinity in the complex8-plane This is an interesting problem, indeed ; however, their results have little generality and the following questions remain What is the initial error for which the increase tends to infinity and what is the initial error for which the increase tends to zero? This paper deeply investigates this problem and completes the solution.