Comparison of rolling friction behavior in HDDs

This paper describe precise modelling about the friction characteristic of Head assembly in HDDs. In the recent research, the track pitch is more and more narrow for the increasing TPI. It is said that it is necessary to suppress the disturbance which was neglected in the part researches and to comprehend a behavior of each disturbance. In the following control system in HDDs, the head assembly was influenced the effect of several disturbances, e.g, RRO, flutter vibration, force disturbance, and so on. At the force disturbance, it caused by wind force, external shock, tension force of Flexible Printed Circuit, and friction. These disturbance recomposed between the cause of disk rotation and other effects. In this paper, we proposed a precise mathematical model of the disturbance caused by friction characteristic without effect of disk rotation. The experimental setup consists of the VCM with head arm and head assembly. The validity of the proposed mathematical model was verified that experimental setup.