Tracking servo control system for reading the eccentric DVD disk at the high-speed

Abstract

A guided servo control system of a high-reading eccentric DVD disc with a robustness which belongs to an electronic information technic field, comprises that: a detection conversion module converts an optical signal of a laser reading / writting device into an electric signal, then compares the electric signal with a system given value to generate an approximate linear guided error signal, an intelligent decision module discriminates whether the disc has eccentricity after processing the guided error signal, if the eccentricity exists, the guided error signal with distortion resulted by the eccentricity is compensated and corrected by a robustness compensation module, then the guided error signal is outputted to a guided servo system; otherwise, the guided error signal is outputted to the guided servo system directly by a common control module. A DVD optical driver of the invention is capable of reading the eccentric DVD disc in a high speed, largely enhancing Run-out anti-interference ability of the DVD system, , performance and success rate of reading the eccentric disc. The control system has a simple format, a good robustness, is capable of limiting an offset resulted by any period interference signal below 167 Hz in a desired range.

Description

Technical field [0001] The invention relates to a servo control system for a DVD optical disc drive, and more specifically, to a tracking servo control system for high-speed reading of eccentric DVD discs. It belongs to the field of electronic information technology. Background technique [0002] The equivalent physical model of the DVD optical drive tracking servo control mechanism can be regarded as a two-car structure. The small car is connected to the big car through a spring and a damper, and there is a complex coupling relationship between them. Among them, the cart corresponds to the coarse adjustment actuator, which is generally a DC brushless motor, which is mainly used for fast and long-distance tracking. It has a large moving range, but the bandwidth is relatively small and the corresponding speed is relatively slow. The trolley corresponds to the fine-tuning actuator. It is a voice coil motor, which carries the laser reader OPU. Its main function is short-distance tra...

AI Technical Summary

Problems solved by technology

Therefore, for an eccentric disc with a maximum amplitude of 50 μm, the optical head deflection of the laser reader cannot exceed 0.022 μm, that is, the ratio of tracking error to disc eccentricity cannot be greater than However, in order to meet this requirement, the standard characteristics of the ideal open-loop tracking servo determine that the rotation frequency of the disc cannot be greater than 23.1 Hz. For a speed higher than 23.1 Hz, the ratio of the tracking error to the eccentricity of the disc will be greater than K 0 , DVD tracking servo system will not meet the requirements

However, the speed of modern DVD has reached 48 times, and the speed of the spindle motor is 9600 rpm, about 160Hz, so the system cannot suppress such a high-frequency run-out disturbance signal, so it cannot read eccentric discs at high speed

[0004] After searching the literature of the prior art, it is found that the Chinese invention patent (application number 01110490.2) proposes an optical drive tracking servo system and method, which is used to control the optical read-write head to track the data track, including: Sensing device, control device, decision-making device and power device are only suitable for discs without eccentricity, and cannot solve the problem of sinusoidal cycle run-out (Run-Out) caused by disc eccentricity, let alone at a speed exceeding 23.1Hz Read eccentric DVD discs at high speed

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