Data based modeling and control of a dual-stage actuator hard disk drive

Abstract

A data-based approach is presented for modeling and controller design of a dual-stage servo actuator in a hard disk drive. The servo actuator in this hard disk drive consists of a conventional voice coil motor and a piezo-electrically actuated suspension. A weighted Hankel matrix based realization algorithm that uses frequency domain data is applied to estimate a discrete-time model of the voice coil motor and the piezoelectric actuator. Based on the discrete-time models, different dual-stage track-following controllers were designed using classic and H∞ loop shaping techniques. The controllers were implemented in real-time in the investigated hard disk drive. A stable feedback control and good agreement between measurement and simulated results show the promising result of data based modeling and control.

Overview of Position Servo Control Technology and Development of Voice Coil Motor

“…Therefore, robust control is especially suitable for those systems with large variation range of uncertain factors and small stability margin [44]- [46]. In [47], H∞ robust control is used to solve the problem of assembly errors in the center of mass and force of VCM; In [48], robust control is used to reduce the impact of load resonance changes; some scholars also propose to use robust control to solve the problem uncertain external disturbance [49]- [51] and the problem of uncertain system model [52], thereby improving the stability and tracking effect of the system.…”