Adaptive Control of Hard Disk Drive Servo System

This paper focuses on the design of an adaptive controller for read/write (R/W) head servo system in a hard disk drive (HDD). In this control system a reference model-based adaptive loop is added to the inner feedback loop with the PID controller. The parameters of the PID controller are computed using PID tuner within Matlab/Simulink. The normalized MIT rule is then used to tune the controller parameters in order to reduce an error between the reference model and actual system. The main objective is to provide accurate and fast positioning of the R/W head and to ensure a fast response of the arm actuator. The performance of the designed system is evaluated through simulations taking into account an influence of changes in the system parameters as well as the effect of external disturbances acting.