GB1423706A - Coarse and fine control for position servo - Google Patents

Coarse and fine control for position servo

Info

Publication number
GB1423706A
GB1423706A GB2254773A GB2254773A GB1423706A GB 1423706 A GB1423706 A GB 1423706A GB 2254773 A GB2254773 A GB 2254773A GB 2254773 A GB2254773 A GB 2254773A GB 1423706 A GB1423706 A GB 1423706A
Authority
GB
United Kingdom
Prior art keywords
tracks
disc
head
coarse
track
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB2254773A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Information Storage Systems Inc
Original Assignee
Information Storage Systems Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Information Storage Systems Inc filed Critical Information Storage Systems Inc
Publication of GB1423706A publication Critical patent/GB1423706A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D3/00—Control of position or direction
    • G05D3/12—Control of position or direction using feedback
    • G05D3/14—Control of position or direction using feedback using an analogue comparing device
    • G05D3/1436—Control of position or direction using feedback using an analogue comparing device with fine or coarse devices
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
    • G11B5/54—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head into or out of its operative position or across tracks
    • G11B5/55—Track change, selection or acquisition by displacement of the head
    • G11B5/5521—Track change, selection or acquisition by displacement of the head across disk tracks
    • G11B5/5552—Track change, selection or acquisition by displacement of the head across disk tracks using fine positioning means for track acquisition separate from the coarse (e.g. track changing) positioning means
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00—Program-control systems
    • G05B2219/30—Nc systems
    • G05B2219/42—Servomotor, servo controller kind till VSS
    • G05B2219/42171—Velocity profile, variable gain, multiplication factors, rom ram

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Moving Of The Head To Find And Align With The Track (AREA)
  • Feedback Control In General (AREA)
  • Moving Of Head For Track Selection And Changing (AREA)

Abstract

1423706 Automatic control of position INFORMATION STORAGE SYSTEMS Inc 11 May 1973 [21 Aug 1972] 22547/73 Heading G3N A servo system which positions a magnetichead 15, Fig. 1, over a selected one of several data tracks on a rotating disc 10 has coarse and fine modes of operation. Associated with disc 10 is a servo disc 11 bearing reference tracks corresponding in position to the data tracks on disc 10. Disc 11 is traversed by a head 16 which is moved together with head 15 by head positioning means 17. As the head 16 moves across the disc towards a desired track it produces a coarse signal as in Fig. 2B which enables the number of tracks crossed to be found. The signal is fed via boxes 19,24 in Fig. 1 to a counter 21 where the number of tracks crossed is subtracted from the number to be crossed before a desired 40 track is reached. When the count indicates zero denoting the passage of the last track proceeding the desired track, a circuit including a tacho-meter 34 and an integrator 35 is enabled to produce a velocity signal, Fig. 2C, which is integrated, Fig. 20, to give a fine position signal representing the position of the head between tracks 029 and 030. When this integrated signal reaches a reference value E set in servo mode detector 22, Fig. 1, the servo 23 is switched from its coarse to a fine mode where it responds to the fine signal and is able to lock on to the desired track 030 without overrun. The system may include a known feature whereby at a plurality of tracks before the desired track (track 27 as illustrated in Fig. 2C). The head movement may be slowed. U.S.A. Specification 3458785 is referred to for an example of a servo system which has coarse and fine modes of operation.
GB2254773A 1972-08-21 1973-05-11 Coarse and fine control for position servo Expired GB1423706A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US28248772A 1972-08-21 1972-08-21

Publications (1)

Publication Number Publication Date
GB1423706A true GB1423706A (en) 1976-02-04

Family

ID=23081724

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2254773A Expired GB1423706A (en) 1972-08-21 1973-05-11 Coarse and fine control for position servo

Country Status (7)

Country Link
JP (1) JPS5148053B2 (en)
CA (1) CA995300A (en)
DE (1) DE2326661A1 (en)
FR (1) FR2197193B1 (en)
GB (1) GB1423706A (en)
IT (1) IT998403B (en)
NL (1) NL7311053A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6262552B1 (en) 1998-01-23 2001-07-17 Metso Paper Automation Inc. Method of positioning an actuator

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1488038A (en) * 1974-12-10 1977-10-05 Ibm Data storage apparatus

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1127992A (en) * 1955-06-16 1956-12-28 Servomecanismes Electroniques Improvements to servomechanisms
GB1114676A (en) * 1963-12-23 1968-05-22 English Electric Co Ltd Control system for an electrically-operated actuator
BE724125A (en) * 1968-11-19 1969-05-19 Acec Position control device
DE2034933A1 (en) * 1970-07-14 1972-01-27 Siemens Ag Disk storage
GB1319227A (en) * 1971-02-15 1973-06-06 Ibm Movement control system

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6262552B1 (en) 1998-01-23 2001-07-17 Metso Paper Automation Inc. Method of positioning an actuator

Also Published As

Publication number Publication date
FR2197193B1 (en) 1976-11-19
FR2197193A1 (en) 1974-03-22
JPS5148053B2 (en) 1976-12-18
NL7311053A (en) 1974-02-25
DE2326661A1 (en) 1974-03-21
CA995300A (en) 1976-08-17
JPS5036105A (en) 1975-04-05
IT998403B (en) 1976-01-20

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee