MODELLING AND CONTROL IN OPTICAL DISK DRIVES: REDUCING THE OPTO-MECHANICAL COUPLING EFFECT

In this paper it is proposed a new radial and vertical disturbance model for Optical Disc Drives (ODD). The model takes into account the optomechanical coupling between the radial and the vertical control loops. As a result, the coupling effect appears as an amplification of the vertical disturbances around the middle and the high frequencies in the vertical control loop (i.e. the focus servo). In addition, this paper proposes a H∞ controller which compensates the coupling effect by choosing a suitable weighting function. The behavior of the controlled system is analyzed and discussed by using a simulation example in the frequency domain. This work has been supported by the European BLAZE Program.