為了抑制光碟機振動之音圈馬達出力控制

Abstract

光碟機之振動，主要是由於旋轉碟片所產生之不平衡力、氣流、碟片變形以及軸承所造成。光碟機通常使用被動式吸振器當作減振裝置。一般來說，光碟機在不同的讀取速率下，會用不同的轉速來運作。但是目前的被動性吸振裝置，只有在某一個轉速下，才能發揮效果；在其它的頻率下甚至還會激發振動。故本研究使用了音圈馬達來形成一個主動式吸振器，搭配順滑模式控制以及以順滑模態為基礎的模糊控制方法，使這個主動式吸振器，能有效抑制光碟機在各個轉速下的振動。由模擬及實驗的結果，顯示順滑模式控制的制振效果，比起以順滑模態為基礎的模糊控制來的好，於轉速 以下抑制光碟機承載台約一半的振動量，轉速 以上時能夠抑制的振動量則減少。

Unbalanced force of disks and bearings in rotation, airflow, and disk deformation will excite vibration of optical disk drives. Passive vibration absorbers are usually used in current optical disk drives to suppress vibration. Generally, optical disk drives have to make a disk spin at multiple speeds for different read/write speeds. However, passive vibration absorbers only suppress vibration at a specific rotating speed and may excite vibration at other speeds. To reduce disk drive vibration at multiple speeds, this study uses sliding mode control and sliding-mode-based fuzzy control for active absorbers with a voice coil motor. Simulation and experimental results show that sliding mode control is more effective than sliding-mode-based fuzzy control. Sliding mode control can reduce about half amplitude of the pickup head mechanism for rotational speed below 6000rpm, while less amplitude at speed above 6000rpm.