Revisiting the regulator problem in the geometric approach, part 1: disturbance localization by dynamic compensation

The aim of this paper is to present a new proof of a well-known fundamental set of necessary and sufficient conditions for disturbance localization by dynamic compensation. Due to a more convenient selection of basic definitions and properties, the arguments herein developed are much more concise and straightforward than those already available in the literature. In Part 2 of the paper, the same approach will be extended to the more general problem of regulator synthesis with plant stability, for which necessary and sufficient conditions significantly different from those already known in the literature will be given.