Robust Adjacent Track Servo System with Linear Positioning Method

Urakawa, Yoshiyuki; Deoka, Yoshihiko; Suzuki, Yuichi; Mukasa, Tomoharu; Horigome, Junichi

doi:10.7567/jjap.51.08ja02

Cited by 3 publications

(3 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One solution to this problem is to use a separate guide layer with a groove structure and multiple recording layers without a groove structure. [6][7][8] This simple disc structure reduces the disc fabrication cost because the process of forming a groove structure on the recording layers is eliminated. However, the practical data transfer rate is thought to be around megabits per second 9 because recorded data are accessed sequentially (bit-by-bit).…”

Section: Introductionmentioning

confidence: 99%

High-speed focus servo control system using Nyquist aperture mounted on a triaxial actuator for holographic disc drive system

2020

View full text Add to dashboard Cite

We have developed a holographic data storage system using angular-multiplexing recording that has a large capacity of 2 TB and a data transfer rate of 1 Gbit∕s. To read a hologram recorded on a holographic disc at high speed, it is necessary to control the relative position shift between a hologram recorded on a disc and a readout optical system. However, in angularmultiplexing data storage systems, the optical system has no moving mechanism, unlike conventional optical discs such as Blu-ray Discs™. Therefore, it is difficult to control the disc position with high precision and to reduce the settling time of the positioning because the holographic disc has no physical structure for the position control mechanism to control the relative position shift. In the systems, a disc mounted on a disc stage is moved to a position where the signal-tonoise ratio of the reproduced hologram becomes the maximum value. Hence, we present a servo control system based on a shift of the Nyquist aperture using a real-time position error signal to control the disc position. In experiments, a positioning accuracy of AE15 μm and a settling time of 8.5 ms for our angular-multiplexing data storage system using a nonlinear parabolic focus position error signal have been observed. © The Authors. Published by SPIE under a Creative Commons Attribution 4.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

show abstract

Section: Introductionmentioning

confidence: 99%

High-speed focus servo control system using Nyquist aperture mounted on a triaxial actuator for holographic disc drive system

2020

View full text Add to dashboard Cite

show abstract

“…Since data are recorded on the basis of the recording spot, such a shift can cause previously recorded data marks to be overwritten. One solution to this problem is the adjacent track servo system with linear positioning method developed by Urakawa et al [19][20][21][22][23] However, the need to form a particular pit structure on the servo layer to maintain a continuous linear position on the groove-less disk could increase the disk fabrication cost. An alternative is the advanced radial position control system developed by Tanaka et al, [24][25][26][27][28] but its use of feed-forward control it is not sufficiently robust against shock and vibration.…”

Section: Introductionmentioning

confidence: 99%

Decoupled direct tracking control system based on use of a virtual track for multilayer disk with a separate guide layer

Tanaka

Ogata

Imagawa

2015

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

We developed a decoupled direct tracking control system for multilayer optical disk that uses a separate guide layer. Data marks are recorded on a recording layer immediately above the guide layer by using two spatially separated spots with different wavelengths. Accurate data mark recording requires that the relative positions of the corresponding spots on the recording layer and guide layer are maintained. However, a disk tilt can shift their relative positions and cause previously recorded data marks to be overwritten. Additionally, a two-input/two-output control system is susceptible to mutual interference phenomenon between the two outputs, which can destabilize tracking control. A tracking control system based on use of data marks previously recorded as a virtual track has been developed that prevents spot shifting and mutual interference even if the disk tilt reaches 0.7°, thereby preventing overwriting.

show abstract

“…Moreover, the designing of a feedforward controller is difficult because general optical disk systems do not receive a reference signal. [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] To overcome these problems, we have previously proposed several focusing and tracking control systems such as a robust feedforward tracking controller based on zero phase error tracking (ZPET) feedforward control and prediction of the tracking error. [26][27][28] Generally, the focusing actuator and the tracking actuator are controlled separately.…”

Section: Introductionmentioning

confidence: 99%

Single-rate two-dimensional feedforward control system for optical disk systems in consideration of the phase delay

Ohashi¹,

Yoshida²,

Ohishi³

et al. 2015

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

The size of digital content has been on the increasing in recent times, and this has been led to the need for correspondingly scaling up the capacity of digital storage media. Therefore, a high-precision focusing and tracking control system are required for an optical disk. A pickup system for optical disks operates in the horizontal and vertical directions for tracking and focusing, respectively. Thus, this paper proposes a new single-rate two-dimensional feedforward control system, which is the concurrent control of focusing and tracking. The feedforward controller is based on a zero phase error tracking (ZPET) control. Experimental results show the effectiveness of the proposed control system.

show abstract

Robust Adjacent Track Servo System with Linear Positioning Method

Cited by 3 publications

References 11 publications

High-speed focus servo control system using Nyquist aperture mounted on a triaxial actuator for holographic disc drive system

High-speed focus servo control system using Nyquist aperture mounted on a triaxial actuator for holographic disc drive system

Decoupled direct tracking control system based on use of a virtual track for multilayer disk with a separate guide layer

Single-rate two-dimensional feedforward control system for optical disk systems in consideration of the phase delay

Contact Info

Product

Resources

About