公开(公告)号：JPH10214116A

公开(公告)日：1998-08-11

申请号：JP326498

申请日：1998-01-09

Applicant: IBM

Inventor： DONALD LEE CLAIR ,  LEWIS JOSEPH SERRANO

IPC: G05D3/12 ,  G11B5/55 ,  G11B21/08

Abstract: PROBLEM TO BE SOLVED: To improve a saturation model used for predicting and updating the head position, speed and current, by changing an algorithm model so as to reflect the actual torque coefficient and actual maximum current level of a voice coil motor(VCM) in a saturation seek mode. SOLUTION: A servo system calculates an estimated VCM control value for indicating a VCM current, calculates the estimated value of the state of the VCM including the head position and the speed and calculates the predicted values of the head position and the speed from the algorithm model. For the modeling, the algorithm model is changed so as to reflect the actual torque coefficient and actual maximum current level of the VCM in the saturation seek mode. The improved modeling of the servo system is provided with the ratio K1 of the measured torque coefficient in the saturation seek mode and a nominal torque coefficient and the ratio K2 of a measured maximum acceleration and a nominal maximum acceleration and incorporates estimated static windage to prediction performed by the saturation model.

公开(公告)号：JP2000021105A

公开(公告)日：2000-01-21

申请号：JP16617699

申请日：1999-06-14

Applicant: IBM

Inventor： MARIO BROWN ,  WILLIAM JOHN CABELACK ,  LEWIS JOSEPH SERRANO ,  MANTLE MAN-HON YU

IPC: G11B5/596 ,  G11B5/012 ,  G11B5/82 ,  G11B20/18 ,  G11B21/10 ,  G11B27/30

Abstract: PROBLEM TO BE SOLVED: To provide a disk to be used in a dive drive and a method of manufacturing the same disk. SOLUTION: In the position error signal(PES) field of every track on the disk, encoded predetermined data, for example, servo data is written. In the preferred embodiment, a) data, for example, track number is mapped to the code word of error correcting code(ECC), b) code is encoded for further redundancy using a bit vector and c) unprocessed data written to the PES field is restricted and an analog signal characteristic used by the servo system for positioning is equalized. Therefore, this method enables that PES field can be used as the source of digital data recorded with resistance to trouble while it is used as in the prior art.

公开(公告)号：JP2000339821A

公开(公告)日：2000-12-08

申请号：JP2000122996

申请日：2000-04-24

Applicant: IBM

Inventor： JEFFREY JOSEPH DOBEC ,  ROWAN BRYAN SCOTT ,  LEWIS JOSEPH SERRANO ,  MANTORU MAN HON YUU

IPC: G11B19/20 ,  G11B19/28 ,  G11B21/02 ,  G11B21/21 ,  H02P29/00 ,  G11B19/02 ,  H02P5/00

Abstract: PROBLEM TO BE SOLVED: To reduce latent possibility of delay in a servo control loop at the time of achieving an appropriate spindle speed by compensating previously drag effect in head loading from a lamp position of a disk drive. SOLUTION: A feed forward control device 30 including a control loop is provided in a form of firmware, drag variation during head loading operation is decided, appropriate control is applied to a spindle motor 16 using expected drag variation, and drag variation is previously compensated. That is, expected drag variation follows the prescribed variation generated by the prescribed servo mechanism system. The control device 30 compensates previously expected drag variation, and provides a feed forward control signal generating a control output signal converted by a D/A 12 to a motor pre-driver 14 by combining with an output signal of a control device of a digital control device 32. Therefore, control in which the speed of the spindle motor 16 is limited in a specified tolerable range is performed during head load process.

公开(公告)号：JP2000011565A

公开(公告)日：2000-01-14

申请号：JP16616599

申请日：1999-06-14

Applicant: IBM

Inventor： MARIO BROWN ,  WILLIAM JOHN CABELACK ,  LEWIS JOSEPH SERRANO ,  MANTLE MAN-HON YU

IPC: G11B5/596 ,  G11B20/18 ,  G11B21/10

Abstract: PROBLEM TO BE SOLVED: To provide error correcting and detecting method and device for retrieving prescribed data, servo data, for example, from a disk position error signal(PES) field in a data storage device. SOLUTION: In a preferable embodiment, PES data, a truck number, for instance, is mapped into a cord word of an error correcting coding(ECC), the cord word is further divided into one set of symbols, and these symbols are mapped into a second bit/vector group having a specified weight. A preferable encoding method is selected in order to equalize an analog signal characteristic of the PES field. As a result, the change in the conventional servo detector is made to a minimum, even if necessary, as this PES field is used as both of the analog information and digital information.

公开(公告)号：JPH10255417A

公开(公告)日：1998-09-25

申请号：JP3689298

申请日：1998-02-19

Applicant: IBM

Inventor： LEWIS JOSEPH SERRANO ,  MANTLE MAN-HON YU

IPC: G11B5/596 ,  G11B20/12 ,  G11B21/08 ,  G11B21/10 ,  G11B27/30

Abstract: PROBLEM TO BE SOLVED: To provide a method and device for writing the binary servo data in a servo burst incorporated on a storage medium of storage device. SOLUTION: Binary servo information contains a track discriminating information such as track number, cylinder number, head number, sector number, index and/or SID(sector identifier). A burst contains tn pieces of time slots (t0 -t7 ), and each slot is provided with a period of a servo burst frequency, and the written is servo data are provided with X pieces of bits of the binary data. Respective (1) bits of the servo data are expressed as the slots (t0 , t3 -t6 ) containing deformation, and respective (0) bits are expressed as empty, e.g. null slots (t1 , t2 , t7 ). By this method, a high bit efficiency system expressing the digital servo data is realized.