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公开(公告)号：DE2648396A1
公开(公告)日：1977-05-18
申请号：DE2648396
申请日：1976-10-26
Applicant: IBM
Inventor： KOSKI JOHN ALEXANDER , LISSNER RUDOLF WERNER , ROBERTS SPENCER DONALD
IPC: G05D13/62 , B65H23/18 , B65H77/00 , G11B15/30 , G11B15/43 , G11B15/46 , G11B15/48 , G11B15/54 , G11B27/13
Abstract: A reel-to-reel web (tape) transport apparatus which has no tape length buffering between the supply and take-up reels. The tape follows a fixed length path from the supply reel, past a read/write head and guides, to a take-up reel. A two motor control mechanism is employed in which one motor drives the take-up reel and one motor drives the supply reel to maintain the appropriate tension and tape motion at the read/write head. The control mechanism is adaptive to dynamic changes as the tape is moved from the supply reel to the take-up reel. Three quantities are monitored: lineal tape position and the angular reel displacement of the supply and take-up reel. From these quantities reel radii are derived, tape inertia calculated and the velocity or position error is determined. A motor current algorithm is utilized to generate the appropriate torque for each reel to drive the control error to zero along a predetermined profile with negligible tape tension disturbances. The result is a reel-to-reel tape drive with static and dynamic performance characteristics which are independent of reel radius and inertia changes resulting from tape motion.
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公开(公告)号：MY119099A
公开(公告)日：2005-03-31
申请号：MYPI20004755
申请日：2000-10-11
Applicant: IBM
Inventor： KOSKI JOHN ALEXANDER , BUI NHAN
Abstract: A CURRENT MODE PULSE WIDTH MODULATION (PWM) TECHNIQUE FOR BRUSHLESS MOTORS. THE PRESENT SYSTEM AND METHOD CONTROLS A BRUSHLESS MOTOR BY INCREASING OR DECREASING MOTOR SPEED RESPECTIVELY ACCORDING TO THE POLARITY AND VALUE OF A PULSE WIDTH MODULATION (PWM) CONTROL SIGNAL.THE PWM SIGNAL VARIES ACCORDING TO AN ERROR SIGNAL GENERATED IN PROPORTION TO THE DIFFERENCE BETWEEN A DESIRED MOTOR CURRENT AND AN ACTUAL MOTOR CURRENT.A MOTOR CURRENT SENSOR IS USED TO SENSE AN ACTUAL MOTOR CURRENT BEING APPLIED TO THE MOTOR.A CURRENT COMPARATOR IS USED TO COMPARE THE CURRENT DESIRED REFERENCE SIGNAL AND THE ACTUAL CURRENT SIGNAL AND TO GENERATE AN ERROR SIGNAL. A PULSE WIDTH MODULATOR IS USED TO CONVERT THE ERROR SIGNAL TO A PULSE-WIDTH MODULATED ERROR SIGNAL. ARMATURE POSITION SENSORS ARE USED FOR SENSING ARMATURE POSITIONS OF THE MOTOR. A COMMUTATOR CIRCUIT RECEIVES THE PULSE-WIDTH MODULATED ERROR SIGNAL AND THE ARMATURE POSITIONS OF THE MOTOR.POWER SWITCHES ARE COUPLED TO OUTPUTS OF THE COMMUTATOR AND ALSO COUPLED TO THE MOTOR.THE COMMUTATOR CONTROLS ACTIVATION AND DEACTIVATION OF THE RESPECTIVE POWER SWITCHES BASED ON THE CORRESPONDING PULSE-WIDTH MODULATED ERROR SIGNAL TO CONTROL THE MOTOR AT A DESIRED MOTOR CURRENT THAT CORRESPONDS TO THE DESIRED REFERENCE CURRENT SIGNAL.THE COMMUTATOR CONTROLS THE RESPECTIVE POWER SWITCHES TO DRIVE THE MOTOR IN EITHER A MORE POSITIVE,A MORE NEGATIVE DIRECTION, OR IN THE SAME MANNER TO RESPECTIVELY INCREASE,DECREASE,OR MAINTAIN THE MOTOR SPEED WHEN THE ERROR SIGNAL CORRESPONDINGLY HAS A GENERALLY POSITIVE,NEGATIVE, OR ZERO VALUE.FIGURE 1
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Patent Agency Ranking
公开(公告)号：AT275752T
公开(公告)日：2004-09-15
申请号：AT01947657
申请日：2001-07-06
Applicant: IBM
Inventor： BUI NHAN XUAN , KOSKI JOHN ALEXANDER , SASAKI AKIMITSU , TSURUTA KAZUHIRO
Abstract: A method and position control for a servo system for positioning a head laterally with respect to defined servo tracks. The servo system comprises a servo sensor and detector for sensing lateral position of the head and a compound actuator having a fine actuator portion and a coarse actuator portion. The position control provides position indications for the coarse actuator portion, which may comprise a table relating predetermined nominal lateral position indications to the defined servo tracks. The position control positions the coarse actuator portion at an estimated position with respect to the defined servo tracks, and responds to the servo sensor to determine which servo track is closest to the estimated position. The position control sets the coarse actuator portion position indication to the predetermined nominal lateral position indication of the closest defined servo track, e.g., by looking it up in the table. This thereby corrects the indication of the position of the coarse actuator portion.
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公开(公告)号：MY117516A
公开(公告)日：2004-07-31
申请号：MYPI20001979
申请日：2000-05-08
Applicant: IBM
Inventor： BUI NHAN XUAN , FUKUDA JUNICHI , JAQUETTE GLEN ALAN , KOSKI JOHN ALEXANDER , TSURUTA KAZUHIRO
Abstract: DISCLOHSED ARE A METHOD AND A DETECTOR FOR ADAPTIVELY DETECTING SERVO GAPS IN A TIMING BASED SERVO PATTERN PRERECORDED ON A VARIABLE MEDIA.THE TIMING BASED SERVO PATTERN HAS GROUPS OF REPEATED PAIRS OF NON-PARALLEL TRANSITION STRIPES ARRANGED IN BURST, THE BURST SEPARATES BY SERVO GAPS WHOSE LENGTH IS VARIABLE. ASERVO SYSTEM SENSOR SENSE THE TRANSITION STRIPES IN THE LONGITUDINAL DIRECTION OF THE MEDIA. AGROUP INTERVAL DETECTOR COUPLED TO THE SENSOR DETECTS THE TIMING INTERVAL BETWEEN THE SAME SLOPE TRANSITION STRIPES OF TWO SEQUENTIAL GROUPS OF BURST. A DIVIDER DIVIDES THE DETECTED GROUP TIMING INTERVAL BY A PREDETERMINED DIVISOR TO PROVIDE A DIVIDED TIMING INTERVAL GAP DETECTION THRESHOLD .A SEQUENTIAL STRIP INTERVAL DETECTOR COUPLED TO THE SENSOR MEASURES THE TIMING INTERVAL BETWEEN STRIPES, AND A COMPARATOR COMPARES THE DIVIDED TIMING INTERVAL AND THE TIMING INTERVAL, IDENTIFYING A SERVO GAP UPON THE MEASURED TIMING INTERVAL AT LEAST EQUALING THE GAP THRESHOLD. THE DETECTOR RESPONDS TO "VALID" SIGNALS WHICH INDICATE THE VALIDITY OF THE DETECTED GROUP TIMING INTERVAL, REPEATION OPERATION OF THE DIVIDER TO UPDATE THE GAP THRESHOLD , REPEATING OPERATION OF THE COMPARATOR WITH THE UPDATED GAP THRESHOLD TO CONTINUE TO IDENTIFY THE SERVO GAPS.
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公开(公告)号：HU0201447A2
公开(公告)日：2002-08-28
申请号：HU0201447
申请日：2000-05-18
Applicant: IBM
Inventor： BUI NHAN XUAN , JAQUETTE GLEN ALAN , KOSKI JOHN ALEXANDER , TSURUTA KAZUHIRO
Abstract: A system and method for precisely registering and synchronizing data sets on a recording media having a prerecorded servo pattern. The recording media is subject to continuing movement for reading and/or writing the data sets, interrupted by stopping at the end of a selected data set and restarting. During the continuing movement of the recording media, a detector coupled to the servo system continuously reads linear position registration data modulated into the prerecorded servo pattern. An interpolator interpolates the prerecorded registration data to provide precision registration information for the data sets. Upon the drive stopping the recording media, then back hitching the media and the movement restarting, selected read and interpolated registration information is provided. The detector again reads and interpolates the prerecorded registration data, and a comparator compares the again read and interpolated registration information to the provided read and interpolated registration information and any predetermined offset, and indicates a comparison match. A data formatter coupled to the comparator, responsive to the comparison match indication, synchronizes the reading and/or writing of data sets on the recording media.
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公开(公告)号：CZ20014146A3
公开(公告)日：2002-02-13
申请号：CZ20014146
申请日：2000-05-18
Applicant: IBM
Inventor： BUI NHAN XUAN , JAQUETTE GLEN ALAN , KOSKI JOHN ALEXANDER , TSURUTA KAZUBIRO
Abstract: A system and method for precisely registering and synchronizing data sets on a recording media having a prerecorded servo pattern. The recording media is subject to continuing movement for reading and/or writing the data sets, interrupted by stopping at the end of a selected data set and restarting. During the continuing movement of the recording media, a detector coupled to the servo system continuously reads linear position registration data modulated into the prerecorded servo pattern. An interpolator interpolates the prerecorded registration data to provide precision registration information for the data sets. Upon the drive stopping the recording media, then back hitching the media and the movement restarting, selected read and interpolated registration information is provided. The detector again reads and interpolates the prerecorded registration data, and a comparator compares the again read and interpolated registration information to the provided read and interpolated registration information and any predetermined offset, and indicates a comparison match. A data formatter coupled to the comparator, responsive to the comparison match indication, synchronizes the reading and/or writing of data sets on the recording media.
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公开(公告)号：DE2855790A1
公开(公告)日：1979-07-12
申请号：DE2855790
申请日：1978-12-22
Applicant: IBM
Inventor： KOSKI JOHN ALEXANDER , WEAVER BRUCE RICHARD
Abstract: Apparatus and method for controlling a reel-to-reel tape drive so that its performance characteristics are optimized to best suit the operational mode or availability of a host system by modifying tape speed adaptively according to predetermined conditions sensed during processing of data (i.e., while the tape is in motion). For example, tape might initially be fed at a high speed suitable for archiving; but if more than a predetermined number of "backhitches" (overruns of the interblock gap, IBG) occur during processing of a preselected number of successive blocks of data, the host will cause tape speed automatically to be reduced to a lower rate. This lower rate will enable the tape to stop in the IBG and is therefore suitable for intermittent processing. Preferably, before reducing speed during write operations, appropriate signals are generated at the host to command an increase in the IBG from a normal distance to a larger distance if backhitches exceed said preselected number. If this fails to reduce backhitches to an acceptable level, speed will be reduced to the lower rate and the gap preferably restored to its normal distance.
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