US3579072A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Servo position control including integral control in foreward and feedback controls
Assignee: Rank Organization Ltd
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Filing: 1968-10-21
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Granted: 1971-05-18
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Expires: 1988-10-21
Abstract
Abstract A control system for an actuator, for example, a positional control motor for a camera, includes a demand unit which provides demand signals representative of different positions or energization levels of the actuator. A control signal is generated by an integrator which is responsive to the demand signal and which compares the change in demand with the state of the actuator immediately before the commencement of the change, as indicated by a memory signal provided by a further integrator. This control signal, and the actuator energization level, changes at a rate dependent upon, and preferably proportional to, the change in demand. Preferably, therefore, the system is such that a given change in actuator energization takes place in a time interval which is independent of the magnitude of the change in demand.
Inventors
- 👤 Dexter Robert Plummer
- 👤 Keith Lawrence Wright
- 👤 Colin Arthur Wild
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 10:29
CPC Classifications
G; G05; G05D; G05D3/00; G05D3/12; G05D3/14; G05D3/1445
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
184 words
A control system comprising in combination: an actuator, a demand unit providing a demand signal representative of a demanded level of energization of the actuator, a reset device operatively associated with the actuator and providing a feedback signal indicative of the level of energization of the actuator, an integrator means for said feedback signal, a normally closed switch conneCting the integrator means to the reset device to integrate the feedback signal, means effective to open said switch automatically upon a change in the demand signal to store in the integrator means a memory signal representative of the level of energization of the actuator at the commencement of a change in said level, control signal generating means comparing the demand signal with the memory signal to provide a control signal representative of the change in demand, actuator control means controlling the level of energization of the actuator in response to said control signal, at a rate dependent upon the magnitude of the change in demand, and means maintaining constant the level of energization of the actuator upon completion of a demanded change in said level.
Claim 2
Dependent Claim
184 words
A control system comprising in combination: an actuator, a demand unit providing a demand signal representative of a demanded level of energization of the actuator, a reset device operatively associated with the actuator and providing a feedback signal indicative of the level of energization of the actuator, an integrator means for said feedback signal, a normally closed switch conneCting the integrator means to the reset device to integrate the feedback signal, means effective to open said switch automatically upon a change in the demand signal to store in the integrator means a memory signal representative of the level of energization of the actuator at the commencement of a change in said level, control signal generating means comparing the demand signal with the memory signal to provide a control signal representative of the change in demand, actuator control means controlling the level of energization of the actuator in response to said control signal, at a rate dependent upon the magnitude of the change in demand, and means maintaining constant the level of energization of the actuator upon completion of a demanded change in said level.
Claim 3
Dependent Claim
31 words
A control system as claimed in claim 1, wherein the control signal generating means include an integrator which integrates an input signal derived from the demand signal and said memory signal.
Claim 4
Dependent Claim
74 words
In a television or motion picture camera a control system as claimed in claim 1, wherein the actuator is operatively associated with a movable component of the television or motion picture camera, the rate of movement of the actuator being dependent upon the magnitude of a positional demand change, the said means maintaining constant the level of actuator energization being effective to halt movement of the actuator when the demanded change has been effected.
Claim 5
Dependent Claim
63 words
A control system as claimed in claim 1, wherein the said control signal generating means provide a control signal which varies substantially linearly with time at a rate substantially proportional to the magnitude of the demand change, whereby the change in the level of actuator energization takes place in a time interval which is substantially independent of the magnitude of the demand change.
Claim 6
Dependent Claim
27 words
A control system as claimed in claim 1, including means effective to vary the rates of change of the control signal which correspond to given demand changes.
Claim 7
Dependent Claim
49 words
A control system as claimed in claim 4, including a plurality of different respective actuators which share operating time with a common said control signal generating means, whereby changes in the levels of energization of said actuators are completed within time interval irrespective of the magnitudes of the changes.
Claim 8
Dependent Claim
37 words
A control system as claimed in claim 4, including an interval timer which is operative to halt the change in actuator excitation level automatically after said predetermined time interval following the initiation of the change in demand.
Claim 9
Dependent Claim
68 words
A control system as claimed in claim 4, including a timer adapted to initiate opening of the normally closed switch upon a change in the demand signal and, after the said time interval, to reclose said switch, whereby the memory signal provided by the integrator means throughout said interval is representative of the level of energization of the actuator at the commencement of the said change in demand.
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) | 1974-05-17 | 1974-11-16 | 1975-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-17 | 1978-11-16 | 1979-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-17 | 1982-11-16 | 1983-05-18 | $7700.00 | Window Closed / Lapsed |