US5093609A
Expired / Lapsed
US
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Servomotor control method
Assignee: Fanuc Corp
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Filing: 1989-01-12
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Granted: 1992-03-03
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Expires: 2009-01-12
Abstract
Abstract A servomotor control method controls a servomotor stably at a high speed. A control loop is switched from a PI control mode to an I-p control mode by varying a gain coefficient of a proportional arithmetic unit (1). This achieves a control process having the advantages of both the PI and I-p control modes.
Inventors
- 👤 Keiji Sakamoto
- 👤 Shinji Seki
- 👤 Yasusuke Iwashita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:15
CPC Classifications
G; G05; G05B; G05B11/00; G05B11/01; G05B11/36; G05B11/42; H; H02; H02P; H02P23/00; H02P23/16
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
100 words
A method of stably controlling a servomotor at a high speed, comprising the steps of (a) reading an error; (b) continuously switching a control loop from a PI control mode to an I-p control mode in accordance with a proportional component of an input as a function of the error, the error function being defined by: when |e|≧Ia, α=1; when |e|<Ia, α=|e|/Ia; where e is the error, Ia is a predetermined error when the function is switched, and α is a variable for switching the gain of the proportional component; and (c) controlling the servomotor with the switched control mode.
Claim 2
Independent Claim
100 words
A method of stably controlling a servomotor at a high speed, comprising the steps of (a) reading an error; (b) continuously switching a control loop from a PI control mode to an I-p control mode in accordance with a proportional component of an input as a function of the error, the error function being defined by: when |e|≧Ia, α=1; when |e|<Ia, α=|e|/Ia; where e is the error, Ia is a predetermined error when the function is switched, and α is a variable for switching the gain of the proportional component; and (c) controlling the servomotor with the switched control mode.
Claim 3
Dependent Claim
14 words
A method according to claim 1, wherein the control loop is a current loop.
Claim 4
Dependent Claim
14 words
A method according to claim 1, wherein the control loop is a speed loop.
Claim 5
Independent Claim
89 words
A method for stably controlling a servomotor at a high speed comprising the steps of: (a) receiving a current command value; (b) producing, in an arithmetic unit, a difference between the current command value and a current output; (c) integrating, in an integrator, the difference and outputting an integrated signal; (d) producing a proportional value of the current command value in a proportional arithmetic unit; (e) adding the integrated signal and the proportional value and obtaining a sum; and (g) outputting the current output to stably control the servomotor.
Claim 6
Independent Claim
89 words
A method for stably controlling a servomotor at a high speed comprising the steps of: (a) receiving a current command value; (b) producing, in an arithmetic unit, a difference between the current command value and a current output; (c) integrating, in an integrator, the difference and outputting an integrated signal; (d) producing a proportional value of the current command value in a proportional arithmetic unit; (e) adding the integrated signal and the proportional value and obtaining a sum; and (g) outputting the current output to stably control the servomotor.
Claim 7
Dependent Claim
23 words
A method according to claim 4, wherein the proportional gain is multiplied by a variable being in a range between 0 and 1.
Claim 8
Dependent Claim
17 words
A method according to claim 5, wherein the variable is controlled as a function of an error.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-03-03 | 1995-09-02 | 1996-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-03-03 | 1999-09-02 | 2000-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-03-03 | 2003-09-02 | 2004-03-03 | $7700.00 | Window Closed / Lapsed |