Triple-Stage-Actuator System of Head-Positioning Control in Hard Disk Drives

2013 ◽  
Vol 49 (6) ◽  
pp. 2738-2743 ◽  
Author(s):  
Takenori Atsumi ◽  
Shigeo Nakamura ◽  
Masaru Furukawa ◽  
Irizo Naniwa ◽  
Junguo Xu
Keyword(s):  
Hard Disk Drives ◽  
Hard Disk ◽  
Disk Drives ◽  
Positioning Control ◽  
Head Positioning ◽  
Actuator System

Head-Positioning Control Using Resonant Modes in Hard Disk Drives

2005 ◽  
Vol 10 (4) ◽  
pp. 378-384 ◽  
Author(s):  
T. Atsumi ◽  
T. Arisaka ◽  
T. Shimizu ◽  
H. Masuda
Keyword(s):  
Hard Disk Drives ◽  
Hard Disk ◽  
Disk Drives ◽  
Positioning Control ◽  
Resonant Modes ◽  
Head Positioning

HEAD-POSITIONING CONTROL IN TRIPLE-STAGE-ACTUATOR ENTERPRISE HARD DISK DRIVES USING MIXED H2/H∞ SYNTHESIS METHODOLOGIES

2021 ◽  
pp. 1-8
Author(s):  
Zhi Chen ◽  
Prateek Shah ◽  
Roberto Horowitz
Keyword(s):  
Hard Disk Drives ◽  
Voice Coil Motor ◽  
Hard Disk ◽  
Data Driven ◽  
Disk Drives ◽  
Positioning Accuracy ◽  
Positioning Control ◽  
Model Based ◽  
Head Positioning ◽  
Resonance Frequencies

Abstract The recent rapid growth in the cloud storage industry has strongly increased the demand for high-capacity hard disk drives (HDDs). Increasing the areal density brings new challenges to the high-accuracy head-positioning control in the next generation HDD development. Triple-stage-actuator (TSA) system is one of the emerging technologies that can achieve higher bandwidth than that of a dual-stage-actuator (DSA) system and improve the track-following performance. In this paper, we focus on the track-following controller design for TSA system with one voice coil motor (VCM) and two piezoelectric (PZT) actuators. Two types of mixed H2/Hinf synthesis methodologies based on model-based optimization and data-driven optimization are proposed to design the track-following controller for the TSA system. The TSA system can increase the bandwidth of the servo system and decrease the sensitivity to disturbances at the low-frequency range. While increasing the stroke limitation and the resonance frequency of the micro-actuator, the 3sigma the position error signals (PES) is reduced. The data-driven controller can achieve comparable head-positioning accuracy to the model-based controller when it converges to a local optimal solution. The simulation results show the feasibility and effectiveness of the TSA systems with a tertiary PZT actuator. We also analyze the effects of stroke limitations and resonance frequencies of the second/third-stage PZT actuators on the head-positioning accuracy. The results might provide a guideline for the TSA mechanical design.

Head-Positioning Control of Hard Disk Drives Through the Integrated Design of Mechanical and Control Systems

2009 ◽  
Vol 3 (3) ◽  
pp. 277-285 ◽  
Author(s):  
Takenori Atsumi ◽  
Keyword(s):  
Control Systems ◽  
Hard Disk Drives ◽  
Integrated Design ◽  
Hard Disk ◽  
Disk Drive ◽  
Nanometer Scale ◽  
Disk Drives ◽  
Positioning Control ◽  
Head Positioning ◽  
And Control

A Hard Disk Drive (HDD) is an inexpensive mass-production product, but the head-positioning control systems of HDDs require nanometer-scale positioning performance. Therefore, we have studied head-positioning control systems of HDD using designs which integrate mechanical and control systems to improve their control performance while curbing cost increases. In this paper, we introduce “disturbance suppression in high-frequency ranges through phase stable design for high-order mechanical resonances” and “high servo-bandwidth design through mode shape design of mechanical resonance” as examples of techniques that have been developed and are easily applied to products.

Nano-and Micro-Actuations of Hard Disk’s Head Positioning System: Actuator Design and Evaluation of Performance

2006 ◽  
Author(s):  
Y. Han ◽  
H. S. Tzou
Keyword(s):  
Motion Control ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
High Density ◽  
Positioning System ◽  
Disk Drives ◽  
Micro Actuator ◽  
Head Positioning ◽  
Piezoelectric Elements ◽  
Actuator System

High-density magnetic hard disks are key components in information storage. In high-density hard disk drives (HDD), both super fast track seeking and extremely accurate positioning of the read/write head are required. A new multiDOF piezoelectric micro-actuator with nano-transverse and micro-lateral control of the head positioning system for highdensity hard disk drives is proposed. For the track following control of a head positioning system in the HDD, proper modeling of the system including the voice coil motor (VCM), suspension, slider, and gimbal system is very important. Before further comprehensive analysis of the whole assembly, the design concept and the evaluation of the micro-actuator are focused on in this paper. First, design of the new piezoelectric micro-actuator is illustrated. The design of the new micro-actuator is based on the axial deformation of piezoelectric elements for lateral motion control and the bimorph actuation of piezoelectric elements for transverse nm motion control. Next, mathematical models of the micro-actuator system are defined. Lastly, the micro-actuator system is modeled using the commercial finite element package ANSYS. The results from analytical analysis and FE analysis are compared. Static response of the micro-actuator system is evaluated first, followed by analysis of dynamic response analysis. Static actuations of the new actuator system satisfy both lateral (±0.1μm) and transverse (15nm) specifications. Dynamic analysis of the ultra-precision system suggests that the new piezoelectric micro-actuator improves performance of highdensity hard disk drives by increasing servo bandwidth and decreasing flying height.

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