Periodic Disturbance Rejection Control Based on Observer and Switching in Photo-Conductor Drum with Planetary Gear System

摘要

A servo control architecture is proposed for the photo-conductor drum drive using planetary gears in a production printer. The velocity fluctuation of the photo-conductor drum is one of the main causes of color banding. Most of the velocity fluctuations come from gear eccentricity that is particularly large in injection molded plastic gear. In order to obtain high image quality, a servo controller design for periodic disturbance reduction is needed. Feedback and feedforward controllers are used to achieve higher performance. This paper proposes a new feedforward control strategy to reduce the effects of the periodic disturbances that are caused by the transmission error of the planetary gears. The proposed control strategy, based on a switching scheme and an open-loop observer, compensates the periodic disturbances. The advantage of the proposed method is that periodic disturbances can be reduced without sacrificing feedback performance. An experiment on a prototype is carried out to verify the control performances. The results show that 90[%] of periodic disturbances are reduced by the proposed control algorithm.