- 學位論文
頻率適應控制技術及其應用於光碟機碟片面振與偏擺之抑制
Frequency Adaptive Control Technique and its Application to Disk Wobble and Runout Reduction in Optical Disk Drives
摘要
本論文提出一套稱為頻域適應控制技術(FACT)之適應性控制器以消除週期性干擾對控制系統之影響。 此方法所設計之適應性架構等效於一組線性控制器，構成一種不影響原閉迴路系統之外加控制器。 論文中對週期性干擾之補償，已完成詳細之設計與分析方法。 FACT所使用之適應性法則經證明為漸近性穩定，其適應參數經實驗證明為可收斂。 與適應頻域控制(AFC)相比，理論與實驗的結果顯示FACT能分別地消除直流成份或各階諧波，使得對某些特定諧波之補償不會影響其他未補償之諧波。 FACT應用於數位式FPGA與高倍速光碟機組成的實驗系統，來驗證FACT之各項弁遄C光碟機可操作於多種撥放速度與轉動模式，使碟片週期性偏罈P面振之干擾具有多樣的基本諧波頻率。碟片偏繒鼢`軌及短跨軌伺服之效應及面振對聚焦伺服之影響，經實驗證明能顯著地降低。此外，FACT可應用於以單一閉迴路控制器實現光碟機多重撥放速度之特性。
並列摘要
This dissertation proposes a novel adaptive controller, namely frequency adaptive control technique (FACT) for periodic disturbance cancellation. The proposed adaptive scheme is equivalent to a linear controller and is constructed in a plug-in manner without altering the nominal closed-loop system configuration. A complete design and analysis for the compensation of periodic disturbance is achieved. The proposed adaptive algorithm is shown to be exponentially stable and the adaptive parameters are shown experimentally to be convergent. Compared with adaptive frequency control (AFC) methods, the analysis and experimental results show that FACT provides the ability to address the independence of the DC and harmonics cancellation so that the compensation for specific harmonics will not affect the other ones. The functionalities of FACT are verified through an experimental application system consisting of a digital FPGA system and a high speed optical disk drive (ODD). The ODD is operated at various rotating speeds and modes, which causes various fundamental frequencies of periodic runout and wobble disturbances. It is shown experimentally that the runout effects both on track-following and fine seeking systems, and the wobble effects on focusing system are reduced significantly. Furthermore, FACT is demonstrated to be feasible to the cases that a single set of feedback controller fulfills the multiple playing speeds characteristic in ODDs.