Head-positioning control system for small-sized hard disk drives

✍ Scribed by Takehito Yamada; Shinji Takakura

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 573 KB
• Volume: 79
• Category: Article
• ISSN: 8756-663X
• DOI: 10.1002/ecjb.4420790808

✦ Synopsis

High track density has been achieved by adopting an H, controller with a feed-forward compensator using adaptive filter theory in a sector servo system. In applying the H,,, control theory, a state-space model of an augmented plant was constructed considering the input location of the disturbance. Moreover, to reduce repeatable runout, an experiment involving a feed-forward control system including an adaptive FIR filter was performed. As a result, the head-positioning accuracy was improved by approximately 15 percent compared to the case without f e d forward. A 0.15-pm head-positioning accuracy was achieved. This level of accuracy means that a track density of 310 tracks/mm (8100 TPI) can be realized.