Design of a robust gain-up tracking controller for a stable seek action of an optical disk drive

In this paper, we present a robust gain-up tracking controller design method to control stably the shake of tracking actuator after a seek control. A minimum gain-up tracking open-loop gain is calculated by estimating the shake of tracking actuator and a desired transient response is considered to stabilize quickly the shake of tracking actuator. A robust gain-up tracking controller is designed by considering a robust H_infin control problem with a regional stability constraint. The proposed gain-up tracking controller design method is applied to the gain-up track-following system of a DVD rewritable drive and is evaluated through the experimental results.