A new direct Seek Control Design of Optical Disk Drives

Abstract

This paper is concerned with the seek control of Optical Disk Drives (ODDs). We propose a direct Seek Control Scheme (SCS) that provides fast data access capability and robust stability for high-performance Optical Disk Drives. Although an optical disk drive has a significant advantage of random accessibility, increased rotational speed of a disk and limitations of mechanical structure always make it impossible for the conventional SCS to achieve stable and satisfactory seek performance. The conventional seek control technique utilizes only the coarse actuator without any maneuvering of the fine actuator. In this paper, we analyze the problems that may arise when the conventional SCS is applied to high-speed rotational ODD and propose a new SCS that employs both the coarse and fine actuators. With assistance of the fine actuator, however, the seek control system is designed such that its performance is guaranteed for various disturbances and mechanical limitations. Simulations and experiments show the improvements of the proposed direct SCS implemented on a practical DVD-ROM drive system.