An optimal tracking controller design based on the estimation of tracking vibration quantity

This paper provides a schematic method estimating the tracking vibration quantity occurring in the track-following system of an optical disk drive. A tracking loop gain adjustment algorithm is introduced to estimate accurately the tracking vibration quantity in spite of the uncertainties of the tracking actuator. Finally, the tracking vibration quantity can be estimated from the tracking error and the controller output measured when the drive operates and the compensated actuator model. An optimal tracking controller can be designed from a minimum tracking open-loop gain calculated by the estimated tracking vibration quantity. The proposed vibration quantity estimation and controller design method is applied to the track-following system of an optical recording device and is evaluated through the experimental results(1).