A dual-stage magnetic disk drive actuator using a piezoelectric device for a high track density

1991 ◽  
Vol 27 (6) ◽  
pp. 5298-5300 ◽  
Author(s):  
K. Mori ◽  
T. Munemoto ◽  
H. Otsuki ◽  
Y. Yamaguchi ◽  
K. Akagi
Keyword(s):  
Disk Drive ◽  
Track Density ◽  
Magnetic Disk ◽  
Piezoelectric Device ◽  
Dual Stage ◽  
High Track

Design and analysis of dual-stage servo system for high track density HDDs

2002 ◽  
Vol 8 (2-3) ◽  
pp. 161-168 ◽  
Author(s):  
S.-M. Suh ◽  
C. C. Chung ◽  
S.-H. Lee
Keyword(s):  
Servo System ◽  
Track Density ◽  
Dual Stage ◽  
High Track

Multirate digital control for high track density magnetic disk drives

2003 ◽  
Vol 39 (2) ◽  
pp. 832-837 ◽  
Author(s):  
Seung-Hi Lee ◽  
Chung Choo Chung ◽  
Sang-Min Suh
Keyword(s):  
Digital Control ◽  
Track Density ◽  
Disk Drives ◽  
Magnetic Disk ◽  
High Track

Hysteresis Modeling and Inverse Feedforward Compensation for PZT Actuator in Dual-Stage Hard Disk Drive

2013 ◽  
Vol 740 ◽  
pp. 152-158
Author(s):  
Md. Arifur Rahman ◽  
Poh Wee Han ◽  
Abdullah Al Mamun
Keyword(s):  
Hard Disk Drive ◽  
Hard Disk ◽  
Disk Drive ◽  
Second Order ◽  
Track Density ◽  
Hysteresis Model ◽  
Pzt Actuator ◽  
Secondary Stage ◽  
Dual Stage ◽  
Feedforward Controller

With the growth of hard disk storage, it would be difficult to meet the specification of the high track density with conventional single actuator. Therefore the next generation of high speed hard disk drive uses the concept of dual-stage actuated hard disk drive where a secondary actuator is mounted onto the VCM actuator. This helps to achieve higher servo bandwidth and, therefore, more precise tracking. Improved tracking error allows higher track density and hence higher storage capacity. Piezoelectric actuator has been a popular choice as the secondary stage. However, the piezoelectric actuators exhibit an unavoidablecharacteristic of hysteresis which causes inaccuracies and oscillations in the system responses.In this paper, the hysteresis behaviour is investigated for asuspension based PZT actuator which is used as the secondary actuator of HDD available in the market. The Generalized Prandtl-Ishlinskii (GPI) hysteresis model which is a phenomenological based model is obtained usingnon-linear least square curve-fitting. In the secondexperiment, a second order linear dynamics model of the PZT actuator is obtained using frequency response identificationmethod. High frequency resonance modes of the PZT actuator are eliminated using a notch filter. By integrating the obtained GPI hysteresis model with this second-order lineardynamics, a nonlinear dynamic model and an inverse feedforward controller are developed.Preliminary simulation results demonstrate that inverse feedforward controller can be appliedfor precise tracking of triangular and multiple frequency sinusoidal trajectories.

Experimental Results of Adaptive Periodic Disturbance Cancellation in a High Performance Magnetic Disk Drive

1996 ◽  
Vol 118 (3) ◽  
pp. 416-424 ◽  
Author(s):  
Alexei Sacks ◽  
Marc Bodson ◽  
Pradeep Khosla
Keyword(s):  
Adaptive Algorithm ◽  
High Performance ◽  
Disk Drive ◽  
Experimental Results ◽  
Periodic Disturbance ◽  
Magnetic Disk ◽  
Periodic Disturbances ◽  
Disturbance Cancellation ◽  
Adaptive Feedforward ◽  
High Track

This paper considers the implementation of an adaptive algorithm for periodic disturbance cancellation. It is shown that the maximum rate of adaptation can be calculated precisely based on measurements of the system’s frequency response. The response of the closed-loop system to additional disturbances can also be computed on that basis. The results are verified experimentally on a high track density magnetic disk drive. Excellent matching between the theoretical and experimental results is observed. An improved method is also proposed that leads to faster convergence of the adaptive algorithm and better disturbance rejection capabilities. The results of this paper significantly enhance the ability of the control engineer to design and analyze adaptive feedforward algorithms for a variety of applications where periodic disturbances are encountered.

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