Fast-Seeking Control for Two-Stage Actuator System in Optical Disc Drives

Abstract

We have developed a new fast-seeking method for the control of optical disk drives. Fast-seeking is performed by means of velocity control in two modes. The lens velocity in the first mode, which is estimated using a multi-rate observer, is equal to the pickup unit velocity, and it is controlled in order to prevent the lens from vibrating. The lens velocity in the second mode is equal to the specified target velocity, and it is controlled in order to improve the laser-spot positioning accuracy. A DVD-ROM drive is tested to confirm that the control system we propose significantly improves the seeking capabilities.