Robust feedforward tracking control based on sudden disturbance observer and ZPET control for optical disk recording system

This paper proposes a new robust tracking servo system for optical disk recording system with feedforward controller and sudden disturbance observer. In optical recording systems, the tracking servo system must suppress the influence of sudden disturbance and periodic disturbance. In order to suppress the periodic disturbance, this paper designs the feedforward control system with prediction of tracking error. For suppressing the sudden disturbance, this paper proposes the sudden disturbance observer by using the predictively tracking error. The experimental results point out that the proposed tracking servo system has a precise tracking response against both periodic disturbance and sudden disturbance.