Almost Disturbance Decoupling: Static state feedback solutions with maximal pole assignment

This paper is concerned with maximal pole placement solutions for the almost disturbance decoupling problem (ADDP) by static state feedback. It is shown that, when solving ADDP by means of high gain state feedback, always are present some fixed finite poles and poles close to infinity in the closed loop system, which can not be freely assigned. A class of ldquooptimalrdquo geometric subspaces with which maximal complementary pole placement can be achieved is characterized. A reliable construction algorithm for such an optimal geometric subspace (resp. the state feedback solution) is also proposed for a particular class of linear systems. An example is proposed to illustrate our contributions.