The periodic disturbances caused by the inherent eccentricity and unbalancing in compact disc systems is one of the prominent radial tracking problems in high-speed and high density optical storage systems. To compensate these periodic disturbances, a learning feedforward compensation (LFF) method is presented and investigated. Computer simulations and experimental evaluation on the high speed CD-ROM product show that the proposed LFF provides a effective way to improve the radial tracking performance by reducing the radial error by 85%
