ストレージボックス内のハードディスクドライブに加わるファン起因外乱の補償方式

抄録

In the magnetic-head positioning control system of a hard disk drive (HDD) for a data center, the disturbances caused by the cooling fans in the storage box have large gains at high frequencies. Therefore, the control system must have low gains of the sensitivity function at high frequencies so that the control system rejects these disturbances. To achieve this, we employed a resonant filter that can decrease the gain of the sensitivity function beyond the servo bandwidth or the mechanical resonant frequencies. In this paper, we proposed a design method for the resonant filter of a dual-stage actuator system in the HDD. Using the proposed method, we implement the resonant filter at high frequencies and provide comparison with the conventional design method. The design results with the HDDs for data centers show that the proposed method rejects the fan-induced disturbances at high frequencies. In addition, the designed control system can handle variations in the mechanical characteristics well with robust performance.