Fuzzy seeking control on high precision hard disk driver

This paper describes the application of fuzzy logic control on the track-seeking motion in the head-positioning servo mechanism of a hard disk. There are two major operations in the head-positioning servo of a hard disk, i.e. seeking and tracking. The seeking controller performs minimum-time movement of the read-write heads from their current track position to a target track specified by the file controller. The dynamic behaviors of the head-positioning servo is highly nonlinear, which make the derivations of an analytic model very difficult. Under the circumstances, the increasingly popular fuzzy logic control which does not require an exact mathematical model seems to be a good alternative in controller design. A fuzzy seeking controller is therefore designed and implemented on a high precision hard disk driver, the Zentek ZM3140. The proposed seeking controller can successfully move the read-write head servo mechanism to the desired target track. The authors´ experimental results also show fast responses and robust behaviors of the servo system