Study of Servo Control System Modeling in Optical Disc Drives

• Main Authors: Wei-Chia Chu, 褚偉嘉
• Other Authors: Jyh-Ching Juang
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/70563805021346726925

碩士 === 國立成功大學 === 電機工程學系 === 87 === In optical disc drives such as CD-ROMs and DVD-ROMs, the servo system is required to maintain robust focus and tracking performance in the presence of disturbances and uncertainties. In order to cast the design problem in the framework of robust control, both the nominal model and its uncertainty bounds are needed. The thesis applied an indirect method to identify the nominal model and uncertainty bound of an optical disc system. In the data acquisition process, the measurement data are contained with effects due to disc wobble, eccentricity, measurement noise, nonlinearities, and vibrations. A screening process is first applied to separate anomalous data. This is followed by an optimization method which is capable of providing the model as well as uncertainty bound. The identified model is consistent with the model derived using physical law.