Discrete-time supervisory control of families of two-degrees-of-freedom linear set-point controllers

This paper describes a discrete-time "high-level" controller, called a ''supervisor," capable of snitching into feedback with a discrete-time single-input/single-outpu (SISO) system, a sequence of linear two-degrees-of-freedom (2-DOF) set-point controllers. Each controller is selected among a family of candidates so as to cause the output of the system to approach and track a constant reference input. It is shown that the proposed supervisor can stabilize the loop and ensure a zero set-point tracking error even if constant load disturbances are present.