Normalized repetitive control for suppressing periodic disturbances amplified by nonrepeating coefficients

Repetitive control (RC) is capable of achieving high control performance for systems subject to periodic disturbances. Many mechatronic applications involve disturbances where periodic signals are modulated by measurable, time-varying factors that may not be periodic. The aim of this paper is to take advantage of such a structure and to utilize the measurable time-varying factor to integrate data normalization into RC. The developed approach involves decoupling of disturbances, to simultaneously reject both the aperiodic and periodic terms in disturbances. A numerical validation on a example with modeling error confirms the capabilities of this framework.