Vibration suppression of hard disk drive mechanism using intelligent active force control

Abstract

One of the key performances of a Hard Disk Drive (HDD) system is its ability to control or suppress the vibration occurred. The fast development of HDD technology such as in the aspect of high transfer rate, large amount of stored data and the emerging of portable HDD have giving a great challenge to researchers to come up with new solutions and effective techniques to control such a non-linear mechanical system accurately and robustly. This study focuses on the implementation of Active Force Control (AFC) scheme together with intelligent control technique which employing Fuzzy Logic (FL) and Iterative Learning Control (ILC) applied to the linear Voice Coil Motor (VCM) actuator in the HDD dynamics. This type of active control technique and vibration model was done through simulation study using MATLAB and Simulink. The performance of the Intelligent Active Force Control (IAFC) system was compared to the traditional proportionalintegral- derivative (PID) control system in terms of tracking performance and system robustness in countering the disturbances, particularly the vibration and friction. The external vibration was modeled as sinusoidal and random form whereas the friction was modeled based on Coulomb friction. Sensitivity analysis of the system output response was conducted with respect to some variations in operating and loading parameters involved in the HDD system dynamics. The simulation results for each type of proposed controllers as well as from what had been discussed in comparative study part affirm the superiority of the proposed control techniques over its counterpart.