Sampled servo position control system

Details Sampled servo position control system Sampled servo position control system

1981-09-21

1983-10-25

Dobeck, B.

Electricity: motive power systems

Positional servo systems

'sampling' systems including miscellaneous 'sampled data'...

360 77, G05B 2102

Patent

active

044121652

ABSTRACT:
Servo records provided at intervals on a record medium are used in a sampled servo system to define data tracks on the medium. Asperities in the medium, or problems arising from the servo writing process can in some instances lead to mis-alignment of a servo path 33 defined by a servo sample with the corresponding desired data track. This causes non-zero position error signals to be produced even when the track following head is accurately positioned over the data track. The problem is solved by measuring the position error signals derived from each servo sample with the head constrained in the correct on-track position. The value of each of these position error signals is then stored as a digital number forming part of a correcting byte in the data section immediately preceding the associated faulty sample. The correction byte also includes a flag bit which is set to demark the next servo sample if the error is so large as to be deemed uncorrectable. Thereafter, in use if the flag bit is unset, the servo system reads the digital number from the correction byte, and uses it to dynamically correct the position error signal from the associated faulty servo sample. If the flag bit is set, the position error signal from the previous sample is carried forward and used instead of the position error signal from the current sample.

REFERENCES:
patent: 3555524 (1971-01-01), Gerber
patent: 3771136 (1973-11-01), Heneghan
patent: 4103314 (1978-07-01), Case
patent: 4168457 (1979-09-01), Rose
patent: 4208679 (1980-06-01), Hertrich
IBM TDB vol. 18, No. 8, 1-76, A. J. Belts "Null Servo Pattern", p. 2656.
Neues aus der Technik, No. 3, 6-16-80, D. E. Wurzburg "Ausrichten der Kopfe in einen Scheibenspeicher", p. 2.
IBM TDB vol. 19, No. 4, 9-76, pp. 1424-1426 J. E. Dohermann "Defect Skipping Among Fixed Length Records in Direct Access Storage Devices".
IBM TDB vol. 13, No. 11, 4-71, p. 3505 "Packwriter Write Correction System" R. S. Palmer & C. A. Walton.
IBM TDB vol. 22, No. 8A, p. 3269 "Track Servo System Compensating Pattern Defects"A. Marla & V. Zimmerman.
IBM TDB vol. 12, No. 11, 4-70, G. R. Santana "Generation of Position Correction Signal for All Disk Pack Surfaces" p. 1891.
IBM TDB vol. 22, No. 8A, 1-80, G. W. Brock et al. "Recording Position Signals on Record Disks", pp. 3127-3130.
"Sampled-Data Control Systems" McGraw Hill 1958, J. R. Ragazzini & G. F. Franklin-Chapter 7, p. 145.
Patents Abstracts of Japan, vol. 1, No. 49, May 13, 1977, p. 3041e 76, "Head Access System of Magnetic Disc Device".
IBM TDB vol. 21, No. 3, 8-78, G. W. Brock & C. H. Kalthoff "Detecting Erroneous Servo in Record Storage Apparatus" pp. 932--933.
IBM TDB vol. 19, No. 6, 11-76, D. E. Griffiths & H. E. Van Winkle "Self-Calibrating Disk Storage Apparatus" pp. 1991-1992.
IBM-TDB vol. 13, No. 11, 4-71 p. 3585 "Packwrite Correction System"R. S. Palmer, C. A. Walton.
IBM-TDB vol. 22, No. 8A, p. 326 "Track Servo System Compensating Pattern Defects" A. Matla & V. Zimmerman.

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