Naohide SAKIMURA, Takahiro OHASHI, Kiyoshi OHISHI^*, and Toshimasa MIYAZAKI

Department of Electrical Engineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2188, Japan

(Received November 30, 2013; Accepted June 21, 2014)

Recently, the scaling up of the storage capacity and data transfer rate of digital storage media has been required. However, increasing in the storage capacity and transfer rate makes optical head control more difficult. Thus, a tracking control system for optical discs must exhibit a high degree of precision control. Consequently, a new two-stage feedforward control (TSFFC) system for high-precision control is proposed in this paper. The proposed system is constructed using two zero phase error tracking (ZPET) control systems based on error prediction and an error-based disturbance observer (EDOB) that uses a notch filter to suppress non periodic disturbances. The proposed control system is designed for DDU-1000 for digital versatile discs (DVDs). The experimental results demonstrate that the proposed system effectively suppresses tracking errors.

Key words: optical disc, two-stage feedforward control, error-based disturbance observer

^*E-mail address: ohishi@vos.nagaokaut.ac.jp