An Analysis Method of Head Positioning Error for Magnetic Disk Drives (Settling Response Analysis)

摘要

Precise positioning and fast access, which increase the areal storage density and improve the data access performance, are required in the head positioning servo system of magnetic disk drives. The analysis of the settling response in one of the most important themes to meet these demands. In this paper, the settling response is decomposed into its contributing modes using an enhanced prony method wcich is one of the experimental modal analysis methods. Mode characteristics, which are damped naturaI frequency, undamped natural frequency, decay rate, damping ratio, initial amplitude and initial phase, are identified. These modes are divided into servo modes and mechanical vibration modes based on the damping ratio in order to recompose a servo response and a mechanical vibration response. Finally, each mechanical vibration mode is evaluated according to its initial amplitude and its decay rate.