Kiyoshi Tateishi

Application of the Sliding-Mode Controller to Optical Disk Drives

The Blu-ray Disc system is considered to be the next-generation optical disk system following the digital versatile disc system. The system has a high numerical aperture and a narrow track, so improved performance is needed for the servo system. A conventional pickup control based on a linear servo system is limited in the improvement of the servo performance. We have investigated a new approach to realizing high accuracy, high speed, and high robustness. One of the new servo systems is the sliding mode controller. We applied the sliding mode controller to the optical disk drive, and we proposed an effective utilization of it. We experimentally confirmed that the sliding mode controller had sufficient playability, which means trace accuracy, accessability, and defect resistance. The sliding mode controller is a promising system for realizing further playability of the high-density optical disk system.