EP0441407A1
Expired / Lapsed
EP
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System for positioning an object
Assignee: Fujitsu Ltd
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Filing: 1991-02-09
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Granted: —
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Expires: 2011-02-09
Abstract
Abstract The present invention proposes a system for positioning a control object such as a magnetic head(1;11)by moving at a high speed such object (1;11)without generation of vibration. An actuator loading the magnetic head (1;11)and an arithmetic control means (3;18)for controlling a drive motor (2;12)of the actuator based on result of digital arithmetics are comprised. The arithmetic control means (3;18)compute target position, target velocity and target acceleration of each sample period in accordance with polynomials indicating predetermined target position, target velocity and target acceleration, output at least one error between the target position, target velocity as a result of arithmetic and position, velocity of the magnetic head (1;11)at every sample period and control the drive motor (2;12)with an added output of the such position error or speed error and target acceleration as a result of the arithmetic.
Inventors
- 👤 Susumu Hasegawa
- 👤 Yoshifumi Mizoshita
- 👤 Kazuhiko Takaishi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 14:49
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/5526; G11B5/553; G11B5/5547; G11B21/00; G11B21/02; B; B41; B41J; B41J19/00; B41J19/18
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
156 words
A system for positioning a control object (1) to a designated target position comprising drive means (2)for moving and positioning said control object(1)and arithmetic control means (3) for controlling said drive means (2) based on the result of digital arithmetics; wherein target position, target velocity and target acceleration are indicated with polynomials of time based on acceleration and deceleration patterns which minimize the square value of the differential value of acceleration of said control object(1); and wherein said arithmetic control means (3)compute target position, target velocity and target acceleration of each sample period using such polynomials, output at least one error between the target position, target velocity as a result of arithmetic and position, velocity of each sample period of said control object (1),control said drive means (2)by means of a composite signal of such position error or velocity error and the target acceleration as a result of arithmetic and thereby position said control object (1).
Claim 2
Dependent Claim
93 words
A system for positioning a control object according to claim 1, wherein said target position is assumed as X₁, said target velocity as X₂, said target acceleration as X₃, seek distance as a, designed seek time as T and polynomials regarding time as X₁ = -60a 0.1(t/T)⁵ - 0.25(t/T)⁴ + (1/6)(t/T)³ X₂ = -60a 0.5(t/T)⁴ - (t/T)³ + 0.5(t/T)² /T X₃ = -60a 2(t/T)³ - 3(t/T)² + (t/T) /T² and the target position X₁, target velocity X₂ and target acceleration X₃ for each sample period are computed in said arithmetic control means (3).
Claim 3
Dependent Claim
79 words
A system for positioning a control object according to claim 2, wherein a data table (4)storing the data indicating the designed seek time T corresponding to the seek distance a of said control object(1)or the inverse of said designed seek time T or the ratio of said designed seek time T and sample period is provided and the target velocity gain and target acceleration gain are decided using the numerical data obtained by retrieving said data table (4) .
Claim 4
Dependent Claim
82 words
A system for positioning a control object according to claim 2 oder 3, wherein the period from start to end of positioning of said control object (1)is normalized by said designed seek time T for each sample period in said arithmetic control means (3) said target acceleration is computed using said normalized time, said target acceleration is multiplied with said target acceleration gain and said result of multiplication is applied to the drive signal to be supplied to said drive means (2).
Claim 5
Independent Claim
73 words
A system for positioning a control object according to anyone of claims 2 to 4, wherein a data table storing the data which indicates said normalized time and normalized position is provided and said target position, target velocity and target acceleration are computed by computing said normalized position from the current position and seek distance a of said control object(1)and said normalized time is obtained by retrieving said table (4)with said normalized position.
Claim 6
Independent Claim
51 words
A system for positioning a control object according to anyone of claims 1 to 5, wherein said control object(1)is composed of a magnetic head which is movable on a magnetic disk and said drive means(2)is composed of an actuator loading a magnetic head and a positioning motor for driving said actuator.
Claim 7
Independent Claim
51 words
A system for positioning a control object according to anyone of claims 1 to 5, wherein said control object(1)is composed of an optical head which is movable on an optical disk and said drive means(2)is composed of an actuator loading an optical head and a positioning motor for driving said actuator.
Claim 8
Independent Claim
52 words
A system for positioning a control object according to anyone of claims 1 to 5, wherein said control object (1)is composed of a print head which is movable on a printing sheet and said drive means(2)is composed of an actuator loading a print head and a positioning motor for driving said actuator.
Claim 9
Independent Claim
207 words
A system for positioning a magnetic disk apparatus consisting of an actuator for moving and positioning a magnetic head (11)to the designated track on a magnetic disk and an arithmetic control means (17,18,19,20)for controlling a drive motor (12)of said actuator based on result of digital arithmetics; wherein said arithmetic control means (17,18,19,20)comprises; three arithmetic circuits (190,195,196)for respectively computing the target position, target velocity and target acceleration of each sample period with polynomials of time of the target position, target velocity and target acceleration generated based on the acceleration and deceleration patterns which minimize square value of the differential value of the acceleration of said magnetic head (11), two arithmetic circuits (191)for estimating position and velocity of each sample time of said magnetic head, a sixth arithmetic circuit (199)for computing at least one error between the target position, target velocity output from said first and second arithmetic circuits and position, velocity output from said fourth and fifth arithmetic circuits, and a seventh arithmetic circuit (200)for adding the target acceleration signal output from said third arithmetic circuit and the position error output from the fourth arithmetic circuit or velocity error signal output from the fifth arithmetic circuit and then outputting a control signal for the drive motor(12)of said actuator.
Claim 10
Independent Claim
108 words
A system for positioning a control object comprising a driver for moving and positioning a control object(1;11)and a controller (3;18)having a means for generating at least one of the target acceleration, target velocity and target position and controlling said driver in accordance with at least one error of position, velocity and acceleration of control object measured or estimated from said control object, characterized in that the differential value of acceleration of said control object(1;11)is continuous and is less than the predetermined constant value during the seek operation and that the positioning is carried out using the target acceleration where the changing rate does not exceed predetermined constant value.
Claim 11
Dependent Claim
68 words
A system for positioning a control object according to claim 10, wherein the target acceleration, target velocity and target position are expressed by the function for normalized time (t/T), F = Σ a₁ (t/T) m using the value (t/T) obtained by normalizing the time t from start to end of the seek operation of the control object(1;11) with the designed seek time T and these functions are used.
References Cited (Backward Citations)
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