Servo experiments for modeling of actuator and windage dynamics in a hard disk drive

This paper presents the results of a parametric identification method for the modeling of the dynamics of a servo actuator and the windage disturbance present in a hard disk drive. The results are obtained with an identification method that is based on a recently introduced extended two-stage method, which enables the estimation of low order complexity models of system and disturbance dynamics on the basis of closed-loop data. As a result, experimental data obtained under realistic servo conditions is used to find low order discrete time models that describe the actuator and windage disturbance dynamics at different locations on the hard disk.