公开(公告)号：ES2152972T3

公开(公告)日：2001-02-16

申请号：ES94480084

申请日：1994-09-06

Applicant: IBM

Inventor： ANDERSON TODD BARRY ,  HAGEN MARK DAVID

IPC: G11B5/596 ,  G11B21/10 ,  G11B5/55

Abstract: A phase modulated servo method and apparatus are provided for use in a disk file. The disk file includes at least one disk mounted for rotation about an axis and the disk has at least one disk surface for storing data. At a predefined location of the disk surface a series of servo tracks of a predetermined high gain servo pattern are written. The predetermined high gain servo pattern includes 360 DEG phase difference information within each data cylinder. The servo tracks are detected for identifying servo phase information.

公开(公告)号：SG47385A1

公开(公告)日：1998-04-17

申请号：SG1996000355

申请日：1994-09-06

Applicant: IBM

Inventor： ANDERSON TODD BARRY ,  HAGAN MARK DAVID

IPC: G11B5/596 ,  G11B21/10 ,  G11B5/55 ,  G11B5/58

Abstract: A phase modulated servo method and apparatus are provided for use in a disk file. The disk file includes at least one disk mounted for rotation about an axis and the disk has at least one disk surface for storing data. At a predefined location of the disk surface a series of servo tracks of a predetermined high gain servo pattern are written. The predetermined high gain servo pattern includes 360 DEG phase difference information within each data cylinder. The servo tracks are detected for identifying servo phase information.

公开(公告)号：DE3787209T2

公开(公告)日：1994-04-21

申请号：DE3787209

申请日：1987-04-28

Applicant: IBM

Inventor： STICH MICHAEL CHARLES ,  OTTESEN HJALMAR ,  RESMAN JOHN BORIS ,  ANDERSON TODD BARRY

IPC: G05D3/14 ,  G11B21/08 ,  G11B21/10 ,  H02P25/06 ,  G11B5/55 ,  G11B21/02 ,  G05B13/00

Abstract: A controller for a voice coil motor driven disk file actuator (10) is described. The device has an online adjustable gain characteristic for controlling movement of the actuator assembly and an estimator (56) that estimates actuator velocity and bias. Forward gain is estimated from position and coil current measurements and compared with a nominal value to create an error signal used to adjust the controller and estimator gain characteristics. The control technique allows changes in the open loop system without changing the closed loop performance. By monitoring loop gain it is possible to alter compensator gains to maintain a constant closed loop performance.