A Robust Track-following Control for the Stable Coarse Seek

Abstract

In this paper, we provide a robust track-following controller design method for the stable coarse seek control. Due to the inaccurate velocity control during a coarse seek, the shake of fine actuator is generated and thus a gain-up track-following control is required to complete stably the coarse seek. To this end, a loop gain adjustment algorithm is introduced to estimate accurately the shake of fine actuator. A weighting function can be properly selected from a minimum tracking gain-up open-loop gain, calculated from the estimated shake quantity of fine actuator. A robust tracking gain-up controller is designed by considering a robust H∞ control problem using the weighting function. The proposed design method is applied to the coarse seek control system of an optical rewritable drive and is evaluated through the experimental results. * 1. 서 론