光碟機跨軌漏數偵測與粗調伺服之研究

Abstract

本論文主要在研究唯讀型光碟機之徑向伺服系統的行為，希望在不更動主 要硬體架構 的前提下，能夠縮短光碟機的平均讀取時間，並針對徑向伺 服系統所遇到的部份問題 利用不同的演算法加以解決。首先針對光碟機 的徑向伺服系統作一番分析與研究，然 後再針對日人小川及伊藤兩位對 光碟機尋軌時發生軌數漏數的偵測與補償演算法再加 以修正，然後再利 用軟體模擬來驗證其可行性。接著針對實際光碟機的粗調致動器系 統設 計控制器，當中使用PID及Fuzzy兩種相當普遍的控制方法來設計，經過模 擬與實 驗的結果發現到必須使用兩組PID控制參數才能全程控制粗調致動 器系統，而使用Fuzzy控制器時，只要一組控制參數即可以處理。最後可 以發現光學讀取頭的定位時間縮短了。 This thesis describes the study of radial servo system of CD- ROM drive.Using the suitable algorithm to overcome some problems of the radialservo system of CD-ROM drive and reduce the access time based on the precondition which not to modify the major structure of the hardware.First, studied and analyzed the radial servo system of CD-ROM drive,then modified the algorithm developed by Ogawa and Ito which to detectand compensate the track-crossing miscount during long distance seeking,and used software simulation to validate the feasibility of the modifiedalgorithm. Second, designedthe controller of the real coarse actuatorsystem of CD-ROM drive using PID and Fuzzy control algorithms. From thesimulation and experiment, we found that there should be two sets of PIDcontrol parameters so that to handle thewhole stroke of the displacementof the coarse actuator. On the contrary,thereis only one set of Fuzzycontrol parameter to do that. Finally, the access time of the CD-ROM driveis reduced.