在提昇光碟機儲存密度及減少存取時間的趨勢下，負責承載碟片的主軸馬達將以極高倍速運轉，在高倍速運轉下的碟片容易激發出振動，其中碟片不平衡所引致之偏心振動在高倍速下更是明顯。 本研究以時頻圖來探討不同轉速下旋轉碟片的動態特性，由實驗結果之時頻圖可清楚看出碟片的偏心及與碟片自然頻率的調變現象，光碟機尋軌伺服為控制音圈馬達來移動讀寫頭，在碟片上的各資料軌讀取資料。如何在高倍速及旋轉碟片偏心所產生的干擾下，降低讀寫頭尋軌誤差並提昇其性能，研究中以適應性前饋干擾消除有效地抑制具有週期性的重複干擾，經由實驗結果顯示，具週期性的重複干擾在適應性前饋干擾消除下明顯地抑制了碟片偏心所產生的尋軌誤差。 攜帶方便，抽取容易是光碟機儲存資料最大的優點，在光碟片置入光碟機的同時，碟片偏心即已產生，當啓動光碟機後，碟片偏心所產生的不平衡，會增加讀寫頭的循尋誤差，希望本研究對消除碟片偏心所產生的循尋誤差能提供些許助益。 In the trend of increasing data storage density and reducing access time is to satisfy the higher data storage device of the optical disk drives, the disk must is driven by the spindle motor in high speed. The vibration of the disk is easily caused in high speed. In the study, the dynamic characteristics of the rotating disk at different speed used the spectrogram of the signal processing will be investigated. The results show the spectrogram is demonstrated on data measured to the transient phenomenon from a run-up rotating disk is effective. In the experiment, the disk eccentricity and the modulation frequencies with natural frequencies of the disk can be clearly observed from the spectrogram. The tracking servo of the optical disk drives is control a voice coil motor which moves a tracking actuator reaches to the data track for the pick up data. The disturbance influencing tracking error results from the eccentricity of the rotating disk in high speed. How to reduce the tracking error and improve tracking performance will be discussed. Adaptive feedforward cancellation (AFC) can effectively cancel the periodic disturbance. The experiment results show the AFC apparently eliminated the tracking error arising from the eccentricity of the rotating disk.
