An optimal hard disk head fly-height control algorithm for soft error rate reduction during the read-write process

Abstract

This paper presents an optimal y-height (FH) control algorithm for soft error rate (SER) reduction during the read-write process. The parameters related to the y-height change were studied to nd the relations occurring when the hard disk drive head is going to contact the disk. The parameters considered in this algorithm are the position error signal (PES) and the voice coil motor digital to analog converter (DAC) values. The study results show that the DAC values change noticeably when the head moves close to the disk. Therefore, the DAC values are used to indicate when the head moves close to the disk and specify FH to reduce SER. From the test results, the proposed algorithm can improve FH with the SER reduced by 6.99% on average when compared with the default FH set from the factory.