US4197577A
Expired / Lapsed
US
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Control system
Assignee: Rolls Royce PLC
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Filing: 1978-07-10
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Granted: 1980-04-08
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Expires: 1998-07-10
Abstract
Abstract A control system of the non-linear type which behaves in a substantially `proportional` manner. The system comprises an error detector which compares the input and output of a plant to obtain an error value, and a control unit which derives from the error value a continuous control signal for the plant. The control signal comprises a linear term which is a linear function of the error signal and a nonlinear damping term which is a continuously variable function comprising the ratio of the rate of change of the error signal and the error itself.
Inventors
- 👤 Christopher L. Johnson
- 👤 Peter J. Stratton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:18
CPC Classifications
G; G05; G05B; G05B11/00; G05B11/01; G05B11/36; G05B11/42; G05B6/00; G05B6/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
94 words
A control system for controlling a plant comprising: an error detector for comparing an input signal with a plant output signal and for producing an error signal (E); and a control unit coupled to said error signal for producing a continuous control signal for said plant, said control signal comprising a linear component which is a linear function of said error signal and a non-linear damping component which is a continuously variable function comprising a term defined by the ratio of the rate of change of said error signal to said error signal itself.
Claim 2
Dependent Claim
94 words
A control system for controlling a plant comprising: an error detector for comparing an input signal with a plant output signal and for producing an error signal (E); and a control unit coupled to said error signal for producing a continuous control signal for said plant, said control signal comprising a linear component which is a linear function of said error signal and a non-linear damping component which is a continuously variable function comprising a term defined by the ratio of the rate of change of said error signal to said error signal itself.
Claim 3
Dependent Claim
36 words
A control system according to claim 1 wherein said continuously variable function comprises a term defined by the modulus of the ratio of the rate of change of said error signal to said error signal itself.
Claim 4
Dependent Claim
18 words
A control system according to claim 2 wherein said continuously variable function further includes a negative constant term.
Claim 5
Dependent Claim
32 words
A control system according to claim 3 wherein said continuously variable function has a zero value whenever the sum of said modulus term and said negative constant term is a negative value.
Claim 6
Dependent Claim
37 words
A control system according to claim 2 further including means for limiting the value of said continuously variable function to a predetermined maximum value at which said maximum value said system operates as a linear control system.
Claim 7
Dependent Claim
28 words
A control system according to claim 1 wherein said linear function of said error signal comprises a term defined by said error signal multiplied by a constant factor.
Claim 8
Dependent Claim
26 words
A control system according to claim 1 wherein said damping term comprises a term ##EQU12## where E represents the rate of change of said error signal.
Claim 9
Dependent Claim
32 words
A control system according to claim 1 wherein said damping term comprises a term ##EQU13## where E represents the rate of change of said error signal and τ represents a first contant.
Claim 10
Dependent Claim
37 words
A control system according to claim 1 wherein said damping term comprises a term ##EQU14## where E represents the rate of change of said error signal, τ represents a first constant and K represents a second constant.
Claim 11
Dependent Claim
158 words
A control system according to claim 2 wherein said control unit comprises: first means for coupling to said error signal and for deriving a first signal defined by |E| where |E| represents the modulus of said error signal; second means for coupling to said error signal and for deriving a second signal defined by E where E represents the rate of change of said error signal; third means coupled to said second means for deriving a third signal defined by 2KE where K is a first constant; divider means coupled to said first and third means for deriving a fourth signal defined by ##EQU15## fifth means coupled to said divider means for deriving a signal defined by ##EQU16## represents the modulus of the ratio of the rate of change of said error signal to said error signal; and multiplier means coupled to said second means and to said fifth means for deriving said damping component defined by ##EQU17##
Claim 12
Dependent Claim
15 words
A control system according to claim 10 wherein each of said means are electronic means.
References Cited (Backward Citations)
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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) | 1983-04-08 | 1983-10-08 | 1984-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-08 | 1987-10-08 | 1988-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-08 | 1991-10-08 | 1992-04-08 | $7700.00 | Window Closed / Lapsed |