Comparative Analysis among Single-Stage, Dual-Stage, and Triple-Stage Actuator Systems Applied to a Hard Disk Drive Servo System

Abstract

In modern times, the design and optimization of different actuator systems for controlling a high-precision position control system represent a popular interdisciplinary research area. Initially, only single-stage actuator systems were used to control most of the motion control applications. Currently, dual-stage actuation systems are widely applied to high-precision position control systems such as hard disk drive (HDD) servo systems. In the dual-stage system, a voice coil motor (VCM) actuator is used as the primary stage and a piezoelectric micro-actuator is applied as the secondary stage. However, a dual-stage control architecture does not show significant performance improvements to achieve the next-generation high-capacity HDD servo system. Research continues on how to fabricate a tertiary actuator for a triple-stage HDD servo system. A thermal positioning controller (TPC) actuator is considered promising as the tertiary stage. The triple-stage system aims to achieve greater bandwidth, track density, and disk speed, with minimum sensitivity and greater error minimization. In this work, these three actuation systems with different combinations of proportional plus integral (PI), proportional plus derivative (PD), and proportional plus integral plus derivative (PID) controller, lag-lead controller, lag filter, and inverse lead plus a PI controller were designed and analyzed through simulation to achieve high-precision positioning. The comparative analyses were done on the MATLAB/Simulink simulation platform.

Servo Controller Design for Triple-Stage Actuator in HDD to Compensate for High-Frequency Fan Vibration

“…Fig. 3 shows the block diagram of the decoupling controller design in the triple-stage actuator system [32], [36].…”

“…The controller of each actuator can be designed independently, which eases the design and evaluation of the control system. This design method has already been employed in the dual-stage actuator system, and expanded for application in the triple-stage actuator system [32], [36]. However, the control bandwidth of the control structure does not reach 10 kHz.…”

“…In the decouple controller design, the controllers C vcm (z), 17 C mil (z), and C mic (z) were designed based on the previous 18 studies [32], [36]. The open loop characteristics and sensitiv-19 ity function characteristics are shown in Fig.…”

Iterative Parameter Optimization for Multiple Switching Control Applied to a Precision Stage for Microfabrication

“…For instance, Wang et al [8] integrated a motor stage and a PZT stage to achieve precision positioning for large travels. Hossain and Rahman [13] designed a triple stage, which consisted of a voice coil motor, a PZT, and a thermal flying-height control. Because the hysteretic effects of PZTs might degrade system performance, advanced control methods are usually applied to improve system performance.…”