POSITION-DEPENDENT DISTURBANCE REJECTION USING SPATIAL-SAMPLING ROBUST REPETITIVE CONTROL WITH ACTUATOR SATURATION AND LOAD UNCERTAINTY

摘要

This paper proposed modification to the previous design of a two degree-of-freedom (TDOF) repetitive control system for a motor/gear transmission system subject to time-varying position-dependent disturbances. The new discrete-position repetitive controller was operated in spatial domain where those periodic disturbances are stationary, i.e. their spatial frequencies do not vary with the nominal operating velocity of the transmission system. Thus, performance of the repetitive controller will not be compromised as the nominal velocity of the system may change due to friction or load variation. Besides, the modified control system also inherited other nice properties, e.g. robustness to actuator saturation and model uncertainties, from the previous design. Simulation and experimental results for a typical 600-dpi laser printer further justified the design by showing significant transmission error reduction. Halftone banding due to periodic transmission errors was also eliminated on printed images for the compensated system.