Patent EP0312219B1 successfully refreshed from Google Patents.
US4612489A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power transmission
Assignee: Vickers Inc
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Filing: 1984-12-20
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Granted: 1986-09-16
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Expires: 2004-12-20
Abstract
Abstract An electrohydraulic servo control system responsive to a load acceleration or velocity command input signal wherein the input command signal is integrated and compared with position feedback from the valve actuator and load to obtain an error signal which controls the actuator. The velocity command input may be multiplied by an exponential factor to compensate for system following error. Another modification contemplates resetting of command signals to compensate for following error and to eliminate dead time upon change of direction of the load by the operator.
Inventors
- 👤 Rajamouli Gunda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:12
CPC Classifications
G; G05; G05D; G05D3/00; G05D3/12; G05D3/14; G05D3/1445
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
122 words
An electrohydraulic servo system comprising a valve actuator adapted to variably position a load, position sensing means coupled to said actuator and load to provide an electrical signal indicative of actual position at said actuator and load, means for receiving a motion command signal, motion command integration means responsive to said motion command signal to provide a position command signal, means for providing an error signal to control said valve actuator as a function of a difference between said actual position signal and said position command signal, and means responsive to said motion command signal independently of said integration means for automatically setting said position command signal equal to said actual position signal when said motion command signal is equal to zero.
Claim 2
Dependent Claim
122 words
An electrohydraulic servo system comprising a valve actuator adapted to variably position a load, position sensing means coupled to said actuator and load to provide an electrical signal indicative of actual position at said actuator and load, means for receiving a motion command signal, motion command integration means responsive to said motion command signal to provide a position command signal, means for providing an error signal to control said valve actuator as a function of a difference between said actual position signal and said position command signal, and means responsive to said motion command signal independently of said integration means for automatically setting said position command signal equal to said actual position signal when said motion command signal is equal to zero.
Claim 3
Dependent Claim
236 words
In an electrohydraulic servo control system which includes a valve adapted to variable position a load, position sensing means coupled to said actuator and load to provide an electrical signal indicative of actual position at the actuator and load, and means for providing an electrical error signal to control said actuator as a function of a difference between said actual position signal and a position command input signal, the improvement for controlling said system as a function of a motion input command and for eliminating creep and dead time associated with a change in motion as said actuator and load, said improvement comprising means for receiving a motion command input signal, integration means responsive to said motion command input signal to provide a first position command signal, means independent of said integration means and responsive to said motion command signal and to said actual position signal to provide a second position command signal equal to said actual position signal, and means operable in a first mode of operation when said motion command signal is unequal to zero to provide said first position command signal as said position command input signal to said means for providing said error signal, and operable in a second mode of operation when said motion command signal is equal to zero to provide said second position command signal as said position command input signal to said means for providing said error signal.
Claim 4
Dependent Claim
236 words
In an electrohydraulic servo control system which includes a valve adapted to variable position a load, position sensing means coupled to said actuator and load to provide an electrical signal indicative of actual position at the actuator and load, and means for providing an electrical error signal to control said actuator as a function of a difference between said actual position signal and a position command input signal, the improvement for controlling said system as a function of a motion input command and for eliminating creep and dead time associated with a change in motion as said actuator and load, said improvement comprising means for receiving a motion command input signal, integration means responsive to said motion command input signal to provide a first position command signal, means independent of said integration means and responsive to said motion command signal and to said actual position signal to provide a second position command signal equal to said actual position signal, and means operable in a first mode of operation when said motion command signal is unequal to zero to provide said first position command signal as said position command input signal to said means for providing said error signal, and operable in a second mode of operation when said motion command signal is equal to zero to provide said second position command signal as said position command input signal to said means for providing said error signal.
References Cited (Backward Citations)
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Cited
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-09-15 | 1990-03-17 | 1990-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-15 | 1994-03-17 | 1994-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-15 | 1998-03-17 | 1998-09-16 | $7700.00 | Window Closed / Lapsed |