Variable stopwrite threshold using kurtosis

摘要

A data storage system according to one embodiment includes a head; a drive mechanism for passing a medium over the head; and a controller electrically coupled to the head. The system calculates a kurtosis value, using the current position error signal sample or derivative thereof, and adjusts a threshold value using the kurtosis value. The standard deviation or variance is compared to the threshold value, and writing is enabled when the standard deviation or variance does not exceed the threshold value.

主权项

1. A data storage system, comprising:
a head; a drive mechanism for passing a medium aver the head; a controller electrically coupled to the head; logic encoded in or available to the controller for measuring a current position error signal; logic encoded in or available to the controller for calculating a standard deviation or a variance using the current position error signal sample; logic encoded in or available to the controller for calculating a kurtosis value, using the current position error signal sample or derivative thereof; logic encoded in or available to the controller for adjusting a threshold value using the kurtosis value; logic encoded in or available to the controller for comparing the standard deviation or variance to the threshold value; logic encoded in or available to the controller for enabling writing when the standard deviation or variance does not exceed the threshold value; logic encoded in or available to the controller for determining a stopwrite threshold based on a standard deviation or a variance at a current position error signal sample when the standard deviation or variance exceeds the threshold value; logic encoded in or available to the controller for determining whether the current position error signal sample exceeds the stopwrite threshold; logic encoded in or available to the controller for disabling writing when the current position error signal sample exceeds the stopwrite threshold; and logic encoded in or available to the controller for enabling writing when the current position error signal sample does not exceed the stopwrite threshold.