Comprehensive Modeling of Friction in a Hard Disk Drive Actuator

Abstract

This paper deals with the modeling of the voice coil motor (VCM) with nonlinearities from friction in the actuator rotary pivot bearing and data flex cable in a hard disk drive (HDD). They are two of major nonlinearities in the VCM motor, which result in large residual errors and deteriorate the performance of head positioning servo systems. The basic idea to build the model of the VCM motor with the nonlinearities is to identify the configuration of the VCM motor through analysis of physical effects and to determine the parameters with the Monte Carlo method to match the measured frequency response. The verification of the identified model shows that the established model is sufficient to characterize the VCM motor with the nonlinearities.