Disturbance attenuation by dynamic output feedback for input-delay systems

This paper addresses the disturbance attenuation problem by output feedback for multivariable linear systems with delayed inputs. To solve this problem, a feedback compensator is used, which is decomposed into an observer part, a state predictive part, and a static feedback part. Then, the analysis of the closed loop system is made on an equivalent linear system without delay. Based on the geometric approach, we solve two different disturbance attenuation problems, providing necessary and sufficient conditions for their solvability.