Ideal error dynamics based design of discrete-time repetitive controllers

This paper deals with the problem of repetitive control for single-input single-output discrete-time systems. An ideal error dynamics is formed by using a discrete attracting law, and the repetitive control law is derived based on the ideal error dynamics. The compensation for periodic disturbances is involved, and tracking performance could be improved so that the periodic disturbances are rejected completely. The steady-state error band, absolute attractive layer and the monotone decreasing region of the error dynamics are derived theoretically, in order to characterize the closed-loop performance with respect to control parameter values. Numerical simulation is conducted to verify the validity of the proposed method.