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Patent EP0335650A2 successfully refreshed from Google Patents.
EP0335650A2
Expired / Lapsed
EP
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Sampled servo motion control system
Assignee: International Business Machines Corp
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Filing: 1989-03-28
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Granted: —
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Expires: 2009-03-28
Abstract
Abstract In a servo controlled device such as a disk drive actuator or a robot that is driven by a DC motor and must seek from one position to another position and settle at the target position in a minimum time, a deadbeat control response can effect settling in a minimum number of servo sample times with no steady state error and no ripple between sampling instants. The device design, initial conditions entering the deadbeat controlled mode and the frequency of servo samples can be used to enable deadbeat control by limiting the control current to a value that will not saturate the motor coil or exceed the linear operating range of the controlled device.
Inventors
- 👤 Hjalmar Holmboe Ottesen
- 👤 Yuzo Nakagawa
- 👤 Shyunji Ono
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 17:00
CPC Classifications
G; G11; G11B; G11B21/00; G11B21/02; G11B21/08; G11B21/081; G11B21/083
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
117 words
A sampled servo control system for moving a device (12) from one location to another location comprising a DC motor (15) connected to the device and servo control means (22) for causing the DC motor to move the device from one location to another target location, the servo control means having a plurality of modes of operation including a seek mode operating to move the device to a position approaching the target location and a settle mode operating to bring the device to said target location, characterised in that the settle mode uses a deadbeat control sequence of a predetermined number of servo data samples to position the device at the target location with no steady-state error.
Claim 2
Dependent Claim
117 words
A sampled servo control system for moving a device (12) from one location to another location comprising a DC motor (15) connected to the device and servo control means (22) for causing the DC motor to move the device from one location to another target location, the servo control means having a plurality of modes of operation including a seek mode operating to move the device to a position approaching the target location and a settle mode operating to bring the device to said target location, characterised in that the settle mode uses a deadbeat control sequence of a predetermined number of servo data samples to position the device at the target location with no steady-state error.
Claim 3
Dependent Claim
48 words
A servo control system as claimed in claim 1 wherein the servo control means comprises a microprocessor (22) including a velocity estimator (25) and a controller (24) with at least one of said estimator and said controller having a characteristic polynomial with the poles located at the origin.
Claim 4
Dependent Claim
51 words
A servo control system as claimed in claim 2, wherein both the velocity estimator and the controller have characteristic polynomials with the poles located at the origin and said predetermined number of data samples does not exceed the sum of the orders of the characteristic polynomials of the estimator and controller.
Claim 5
Dependent Claim
71 words
A disk file including a servo control system as claimed in any preceding claim wherein said device is a transducer which is movable by the DC motor to different concentric tracks on at least one disk of the disk file, said servo data being an indication of the displacement of the transducer from one of said tracks derived from a servo pattern on said disk which is readable by the transducer.
References Cited (Backward Citations)
No citation records indexed.
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