公开(公告)号：GB2487135A

公开(公告)日：2012-07-11

申请号：GB201200428

申请日：2010-09-13

Applicant: IBM

Inventor： PANTAZI ANGELIKI ,  ELEFTHERIOU EVANGELOS ,  JELITTO JENS ,  BUI NHAN XUAN

IPC: G11B5/584

Abstract: Various embodiments for addressing time-varying periodic disturbances in a servo control system are provided. Each of a plurality of coefficients is updated based on an estimation of at least one disturbance frequency. The updated plurality of coefficients is provided to at least one peak filter modifying an input signal of the servo control system. The peak filter is operable in view of the updated plurality of coefficients to cancel at least 10 one of the time-varying periodic disturbances.

公开(公告)号：GB2484229A

公开(公告)日：2012-04-04

申请号：GB201200295

申请日：2010-06-02

Applicant: IBM

Inventor： JELITTO JENS ,  CHERUBINI GIOVANNI ,  HUTCHINS ROBERT ALLEN ,  SANDBERG MELANIE JEAN

IPC: G11B5/584 ,  G11B5/29

Abstract: A method for monitoring a plurality of servo channels, providing a finite state machine ("FSM") comprising a single servo channel mode and a combined servo channel mode, and moving a sequential information storage medium comprising a plurality of servo bands across a read/write head comprising a corresponding plurality of servo sensors. The method further asserts an acquisition flag by a servo channel if that servo channel is tracking a servo pattern, and asserts a bit flag by a servo channel if a new LPOS bit is decoded. If at least one acquisition flag is asserted, the method determines if a bit flag is asserted by a servo channel associated with said asserted acquisition flag, and if an acquisition flag and a bit flag are asserted by a servo channel, the method determines a relative positioning of each servo sensor with respect to an associated servo pattern.

公开(公告)号：DE602007001872D1

公开(公告)日：2009-09-17

申请号：DE602007001872

申请日：2007-01-10

Applicant: IBM

Inventor： CHERUBINI GIOVANNI ,  ELEFTHERIOU EVANGELOS ,  JELITTO JENS ,  HUTCHINS ROBERT

IPC: G11B5/584

Abstract: A fully synchronous longitudinal position (LPOS) detection system is provided for improving the reliability of servo channels in tape systems. The system is based on the interpolation of the servo channel output signal, which is sampled by an analog-to-digital converter (ADC) at a fixed sampling rate, using a clock at a nominal frequency, so that interpolated signal samples are obtained at a predetermined fixed rate, independent of tape velocity. This predetermined fixed rate is defined in terms of samples per unit of length, as opposed to samples per unit of time, which is the measure of the ADC sampling rate. The resolution with which the servo channel signal is obtained at the interpolator output is thus determined by the step interpolation distance.

公开(公告)号：AT438912T

公开(公告)日：2009-08-15

申请号：AT07703759

申请日：2007-01-10

Applicant: IBM

Inventor： CHERUBINI GIOVANNI ,  ELEFTHERIOU EVANGELOS ,  JELITTO JENS ,  HUTCHINS ROBERT

IPC: G11B5/584

Abstract: A fully synchronous longitudinal position (LPOS) detection system is provided for improving the reliability of servo channels in tape systems. The system is based on the interpolation of the servo channel output signal, which is sampled by an analog-to-digital converter (ADC) at a fixed sampling rate, using a clock at a nominal frequency, so that interpolated signal samples are obtained at a predetermined fixed rate, independent of tape velocity. This predetermined fixed rate is defined in terms of samples per unit of length, as opposed to samples per unit of time, which is the measure of the ADC sampling rate. The resolution with which the servo channel signal is obtained at the interpolator output is thus determined by the step interpolation distance.