Structure at inifinity of linear multivariable systems: A geometric approach

The infinite zero structure of linear multivariable systems is investigated via the geometric approach. The basic tools used are the new concepts of almost (
A, B
)-invariant and almost controllability subspaces. These concepts permit advantageous geometric interpretation of infinite zeros. This interpretation is a natural generalization of the finite case. Connection is made with the Smith-McMillan structure at infinity of the transfer matrix.