US4680518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Servomotor velocity control method
Assignee: Fanuc Corp
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Filing: 1986-01-11
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Granted: 1987-07-14
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Expires: 2006-01-11
Abstract
Abstract A servomotor velocity control system according to the present invention control velocity by using an observer for obtaining a sensed value of velocity while estimating motor load torque. When resolution of a rotary encoder is a problem in a region of low motor velocities, this is compensated for to improve the velocity sensing precision in the low-velocity region. In a region of high motor velocities, velocity processing is executed based on the output of the rotary encoder considering the processing time of a CPU. Use or non-use of the observer for obtaining the estimated value of velocity is selected in dependence upon the velocity of the motor.
Inventors
- 👤 Mitsuo Kurakake
- 👤 Keiji Sakamoto
- 👤 Yukio Toyosawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:47
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/19; G05B19/21; G05B19/23; G05B19/231; G05B19/237; G05B19/416; H; H02; H02P; H02P23/00; H02P23/16; G05B2219/00; G05B2219/30; G05B2219/33; G05B2219/33075; G05B2219/37; G05B2219/37344
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
118 words
A servomotor velocity control method in which position information from a rotary encoder mounted on a servomotor driving a mechanical load is fed back and a torque command signal is produced for application to the servomotor, said method comprising the steps of: comparing a reference velocity set for said servomotor and the motor velocity; calculating an estimated value of load torque when the motor velocity is less than said reference velocity; calculating an estimated value of velocity of the servomotor based on position information from said rotary encoder, motor current of the servomotor and said estimated value of load torque; and calculating the torque command signal based on said estimated value of velocity and a velocity command signal.
Claim 2
Dependent Claim
118 words
A servomotor velocity control method in which position information from a rotary encoder mounted on a servomotor driving a mechanical load is fed back and a torque command signal is produced for application to the servomotor, said method comprising the steps of: comparing a reference velocity set for said servomotor and the motor velocity; calculating an estimated value of load torque when the motor velocity is less than said reference velocity; calculating an estimated value of velocity of the servomotor based on position information from said rotary encoder, motor current of the servomotor and said estimated value of load torque; and calculating the torque command signal based on said estimated value of velocity and a velocity command signal.
Claim 3
Dependent Claim
18 words
A servomotor velocity control method according to claim 1, characterized in that said reference velocity is 1500 rpm.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-07-13 | 1991-01-12 | 1991-07-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-13 | 1995-01-12 | 1995-07-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-13 | 1999-01-12 | 1999-07-14 | $7700.00 | Window Closed / Lapsed |