Fault predictive control of compact disk players

Optical disc players such as CD-players have problems playing certain discs with surface faults like scratches and fingerprints. The problem is to be found in the servo controller which positions the optical pick-up, such that the laser beam is focused on the information track. A scheme handling this problem, called feature based control, has been presented in an other publications of the first author. This scheme is based on an assumption that the surface faults do not change from encounter to encounter. This assumption is unfortunately not entirely true. This paper proposes an improvement of the feature based control scheme, such that a prediction step is included. The proposed scheme is compared with the feature based control scheme, in the perspective of handling surface faults, by simulations. These simulations show the improvements given by the proposed algorithm.