Optical Disc Servo Parameter Optimization via Quadratic Curve Approximation
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Solution Overview
Problem
Optical disc apparatuses face challenges in quickly acquiring necessary sample data for optimal parameter settings during servo control adjustments, leading to potential servo errors and increased time requirements due to the need for multiple parameter adjustments and limited ranges for optimal values.
Innovation Solution
The optical disc apparatus employs a method to efficiently acquire sample data by changing parameter settings in a controlled manner, using a least square method to approximate a quadratic curve and adjust parameters like the SA parameter and focus bias parameter to prevent servo errors and reduce adjustment time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple parameter adjustments are performed to acquire sufficient sample data for optimal settings, then the accuracy of parameter optimization is improved, but the adjustment time increases and servo errors may occur
Solution Approach 1:
The patent applies preliminary action by acquiring sample data at multiple predetermined parameter settings before final optimization. The system pre-establishes a relationship between control parameters and evaluation values through advance sampling, enabling rapid calculation of optimal settings without requiring extensive real-time adjustment during actual operation.
Solution Approach 2:
The patent implements feedback by using acquired evaluation values to calculate optimal parameter settings. The system continuously monitors evaluation values (such as jitter values) and uses this feedback information to adjust control parameters, creating a closed-loop optimization process that efficiently converges on optimal settings.
2Reliability
If the parameter adjustment range is limited to avoid servo errors, then the reliability of servo control is improved, but the ability to find optimal parameter settings is reduced
Solution Approach 1:
The patent applies preliminary action by acquiring sample data at multiple predetermined parameter settings before final optimization. The system pre-establishes a relationship between control parameters and evaluation values through advance sampling, enabling rapid calculation of optimal settings without requiring extensive real-time adjustment during actual operation.
Solution Approach 2:
The patent implements parameter changes by systematically varying control parameters within safe ranges to acquire sample data. The system changes parameters in controlled increments, acquiring evaluation values at each step, and uses this data to calculate optimal settings that maximize adaptability while maintaining servo stability.
Data Source
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AI summary
An optical disc apparatus controls a relative position of an optical pickup with respect to a surface of an optical disc medium according to an output signal output from the optical pickup according to information recorded on the optical disc medium to implement servo control for maintaining a state where the information is readable, acquires an evaluation value for information reading accuracy when the servo control is implemented, and calculates a set value of a parameter to be set for the implementation of the servo control based on evaluation values respectively acquired for at least three set values of the parameter while changing the set value of the parameter for the servo control. The optical disc apparatus determines the set value to be set for further acquiring the evaluation value according to the evaluation values acquired for at least two set values of the parameter.