The CD-ROM Drive

Stan, Sorin G.

doi:10.1007/978-1-4757-2843-9

Cited by 44 publications

(16 citation statements)

References 37 publications

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“…The experimental setup consists of a CD player, with the three beam single Foucault detector principle, (more detailed descriptions of the CD players are given in (Stan, 1998) and (Bouwhuis et al, 1985)), a PC with an I/O-card, and some p. 4 hardware in order to connect the CD player with the I/Ocard. Due to the limited computational power of the CPU in the PC, the sample frequency is chosen to 35 kHz.…”

Section: A Experimental Setupmentioning

confidence: 99%

Time localisation of surface defects on optical discs

Odgaard

Wickerhauser²

Proceedings of the 2004 IEEE International Conference on Control Applications, 2004.

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Abstract-Many have experienced problems with their Compact Disc player when a disc with a scratch or a finger print is tried played. One way to improve the playability of discs with such a defect, is to locate the defect in time and then handle it in a special way. As a consequence this time localisation is needed to be as good as possible. Fang's algorithm for segmentation of the time axis is used since it has good performance in an application like this. Fang's algorithm has a clear potential for time localisation for some defects and but not for other defects. Instead the normally used threshold is improved to handle eccentricity and localisation of the end of the defect better.

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Section: A Experimental Setupmentioning

confidence: 99%

Time localisation of surface defects on optical discs

Odgaard

Wickerhauser²

Proceedings of the 2004 IEEE International Conference on Control Applications, 2004.

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“…Both Yeh (see [17]) and Dettori (see [18]) performed some work on the cross-couplings in the mechanical and electromagnetic parts between focus and radial loop. Regarding the optical part of the system the present control strategies are based on simple linear models not considering the optical cross-coupling [15] and [19], although some work has been done regarding the optical model. Some considerations about the optical cross-couplings are done in [17].…”

Section: Introductionmentioning

confidence: 99%

Detection of surface defects and servo signal restoration for a compact disc player

Odgaard

Stoustrup

Andersen

et al. 2006

IEEE Trans. Contr. Syst. Technol.

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Compact disc (CD) players have been on the market for more than two decades, and the involved technologies, including control are very mature. Some problems, however, still remain with respect to playing CDs having to surface defects like scratches and fingerprints. Two servo control loops are used to keep the optical pick-up unit (OPU) focused and radially locked to the information track of the CD. The problem is to design servo controllers which are well suited for both handling surface defects and disturbances like mechanical shocks. The handling of surface defects requires a low-controller bandwidth which is in conflict with the requirement for the handling of disturbances. This control problem can be solved by the use of a fault tolerant control strategy, where the fault detection is very important. The OPU feeds the controllers with detector signals. Based on these, focus and radial distances can be estimated and a pair of residuals can be computed. This paper introduces a model-based method to estimate focus and radial distances as well as residuals, which have the potential to improve the control of a CD player in case of a surface defect. The methods are applied to experimental data of a scratch. The results of this experimental work show the potential of the method.

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“…The focus coils are used to focus the laser beam in the vertical direction, while the radial tracking coils are used to move the OPU in the horizontal direction. Ideally, the movement along each axis can be independently controlled [2], [3], [7]. However, in practice some coupling influence between these two axes has been observed in many standard systems, especially the high speed optical disc drive systems [1], [4], [5], [6].…”

Section: Introductionmentioning

confidence: 99%

“…As a key element in a typical optical disc drive system, the Optical Pick-up Unit (OPU) reads the information from the inserted disc and feedback the OPU position information as well [2], [7]. A standard OPU usually consists of focus and radial tracking coils, photodiodes and a laser diode.…”

Section: Introductionmentioning

confidence: 99%

On the coupled focusing and tracking performances of a high-speed optical disk drive

Yang

Pedersen

Odgaard³

et al. 2008

2008 IEEE International Symposium on Industrial Electronics

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The coupling dynamic between the focusing and tracking axis of a high speed optical disk drive system is exploited from the theoretical and experimental perspectives. By assuming the fact that the coupling dynamic is mainly due to the misalignment of the mass center and centroid of magnetic forces, a mathematical model of considered system is derived according to the first-principle method. Afterwards, experimental testings are carried out to identify some system coefficients and thereby verify the consistency of the theoretical model with practical system. The results turn out that the misalignment of mass center with centroid is not the only dominant reason for coupling, some other coupling mechanisms, such as stiffness coupling of the suspension wires, electro-magnet coupling and some nonlinearities in the system may also play some critical rule in the coupling dynamic. This analysis dedicates some deep insights of coupling phenomena for high speed disk drive, even though some phenomena could be roughly modeled by uncertainties insider the system.

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The CD-ROM Drive

Cited by 44 publications

References 37 publications

Time localisation of surface defects on optical discs

Time localisation of surface defects on optical discs

Detection of surface defects and servo signal restoration for a compact disc player

On the coupled focusing and tracking performances of a high-speed optical disk drive

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