Patent US3925640A successfully refreshed from Google Patents.
US3925640A
Expired / Lapsed
US
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Closed loop control system having plural modes of operation
Assignee: Rolls Royce PLC
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Filing: 1974-03-04
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Granted: 1975-12-09
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Expires: 1994-03-04
Abstract
Abstract A closed loop control system has at least two modes of operation - a rapid response and a damped response whereby an error is reduced to zero rapidly, but with negligible overshoot. The change from one mode to another is made in dependence upon a predetermined ratio between the error and error velocity signals.
Inventors
- 👤 Matthew Duggan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 09:55
CPC Classifications
G; G05; G05B; G05B11/00; G05B11/01; G05B11/36; G05B11/42; G05D; G05D1/00; G05D1/08; G05D1/0808; G05D1/0816
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
161 words
A closed loop control system for controlling a plant in accordance with an input signal to the control system, the system comprising means for receiving an input signal into the plant, means for generating a plant output signal, a comparator for comparing the input and output signals to produce an error signal proportional to the difference between the input and output signals, means for producing an error velocity signal proportional to the rate of change of the error signal, means responsive to said error and said error velocity signals for generating at least two different linear functions of the error and error velocity signals, each of said linear functions corresponding to a different mode of operation of said control system, means for changing from one linear function to another depending upon a predetermined ratio between the error signal and the error velocity signal, and means for producing a continuous plant control signal varying in accordance with one of said linear functions.
Claim 2
Dependent Claim
161 words
A closed loop control system for controlling a plant in accordance with an input signal to the control system, the system comprising means for receiving an input signal into the plant, means for generating a plant output signal, a comparator for comparing the input and output signals to produce an error signal proportional to the difference between the input and output signals, means for producing an error velocity signal proportional to the rate of change of the error signal, means responsive to said error and said error velocity signals for generating at least two different linear functions of the error and error velocity signals, each of said linear functions corresponding to a different mode of operation of said control system, means for changing from one linear function to another depending upon a predetermined ratio between the error signal and the error velocity signal, and means for producing a continuous plant control signal varying in accordance with one of said linear functions.
Claim 3
Dependent Claim
47 words
The control system of claim 1 wherein said means for generating said linear functions includes means responsive to said error signal for deriving a signal proportional to the positive component of said error signal and a second signal proportional to the negative component of said error signal.
Claim 4
Dependent Claim
50 words
The control system of claim 1 wherein said means for generating said linear functions includes means responsive to said error velocity signal for deriving a signal proportional to the positive component of the error velocity signal and a second signal proportional to the negative component of said error velocity signal.
Claim 5
Dependent Claim
156 words
The control system of claim 1 wherein said means for generating said linear functions includes means responsive to said error signal for generating a signal proportional to the positive component of the error signal and a signal proportional to the negative component of the error signal, means responsive to said error velocity signal for generating a signal proportional to the positive component of the error velocity signal, and a signal proportional to the negative component of the error velocity signal, and means for summing said error and said error velocity proportional signals, said means including a first summing unit for summing the error signal and said signal proportional to the positive component of the velocity of error signal, a second summing unit for summing the error signal and said signal proportional to the negative component of said error velocity signal, and a third summing unit for summing the outputs of said first and second summing units.
Claim 6
Dependent Claim
56 words
The control system of claim 4 further comprising means for feeding back the output of said first summing unit to the input of said second summing unit along a negative feedback path and means for feeding the output of said second summing unit into the input of said first summing unit along a negative feedback path.
Claim 7
Dependent Claim
74 words
The control system of claim 4 wherein said means for generating said linear function includes means for converting said signal proportional to the positive component of said error signal to a negative value before being coupled to the input of said second summing unit and means for converting said signal proportional to the negative component of said error signal to a negative value before being supplied to the input of said first summing unit.
Claim 8
Dependent Claim
36 words
The control system of claim 4 wherein said means for generating said linear functions includes means for inverting the output from said second summing unit before said output signal is supplied to said third summing unit.
Claim 9
Dependent Claim
31 words
The control system of claim 1 wherein at least one of the functions of the control signal is unstable or marginally unstable when in operation because of zero or small damping.
Claim 10
Dependent Claim
50 words
The control system of claim 1 wherein the control signal comprises one of three different linear functions, the first function providing an undamped oscillatory system, the second function providing a critically damped system, and the third function providing an overdamped system, and wherein said plant is a double integral plant.
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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) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |