The on-line estimation of Voice coil motor windings resistance In Hard disk drive

In this paper we describe an online estimation procedure, based on an extended Kalman filter (EKF), capable of estimating the VCM coil resistance with a high degree of accuracy. VCM resistance may change by 30% during hard disk drive (HDD) operation, increasing when the disk is performing repetitive seek or decreasing when the disk cools down during track following such variation may lead to an unsatisfactory performance to most of control methods which have applied to the servo-positioning system of HDD. So, it is important for designer to estimate the windings resistance in real time. In order to evaluate the parameter, EKF is a good tool, which has been successfully used in on-line estimation of slowly varying parameters in electric drives