US3791793A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adaptive feed forward-feedback control of the concentration of a selected ion of a solution
Assignee: Leeds and Northrup Co
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Filing: 1972-01-31
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Granted: 1974-02-12
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Expires: 1992-01-31
Abstract
Abstract A control system for controlling the flow of reagent into a reactor for the correction of the concentration of a selected ion in the influent to the reactor so as to provide a desired concentration in the effluent stream from the reactor. A feedback controller having proportional and reset responses is provided to control the flow of reagent to maintain the logarithm of the concentration of the ion in the effluent at its set point. The control signal from the feedback controller is multiplied by a feedforward control signal responsive to changes in the logarithm of the ion concentration of the influent, the effluent set point, and influent flow. The resulting product is then summed with the feedforward control signal to provide the final control signal required to control a linear operator for modification of the reagent flow to maintain the logarithm of the ion concentration in the effluent at the set point.
Inventors
- 👤 P Friedmann
- 👤 W Cohen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:04
CPC Classifications
G; G05; G05D; G05D21/00; G05D21/02; Y; Y10; Y10T; Y10T436/00; Y10T436/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
36 words
The method as set forth in claim 1 in which the step of producing the feedforward control signal is responsive to the pX of the influent and the magnitude of the influent flow to the reactor.
Claim 2
Dependent Claim
39 words
The method as set forth in claim 1 in which the step of producing a feedforward control signal is responsive to the pX of the influent, the magnitude of the influent flow to the reactor, and said set point.
Claim 3
Dependent Claim
43 words
The method as set forth in claim 1 in which the function of the deviation of the pX of the effluent from said set point includes proportional and reset responses to the deviation of the pX of the effluent from its set point.
Claim 4
Independent Claim
148 words
The method for controlling to a set point, the pX of the effluent from a reactor process in which the pX of the influent is modified by the addition of a reagent and the flow of the reagent is a linear function of the magnitude of a final control signal comprising the steps of, producing in response to the pX of the influent, the magnitude of the influent flow, and the set point, a feedforward control signal indicative of the reagent flow required to change the pX of the influent toward the set point, producing a feedback control signal in accordance with the deviation of the pX of the effluent from said set point, and producing a final control signal for modifying the flow of said reagent as a function of the sum of said feedforward control signal and the product of said feedforward and feedback control signals.
Claim 5
Independent Claim
114 words
A system for controlling the pX of the effluent from a process reactor at a predetermined set point by linearly varying the reagent flow to the reactor in response to a final control signal comprising: means responsive to the pX of the influent for producing a feedforward control signal indicative of the reagent flow required to change the pX of the influent to the set point under certain process conditions, and means for producing said final control signal as a function of the weighted sum of said feedforward control signal and the product of said feedforward control signal and a function of the deviation of the pX of the effluent from said set point.
Claim 6
Dependent Claim
36 words
A system as set forth in claim 6 in which the means for producing the feedforward control signal is responsive to the pX of the influent and the magnitude of the influent flow to the reactor.
Claim 7
Dependent Claim
39 words
A system as set forth in claim 6 in which the means for producing the feedforward control signal is responsive to the pX of the influent, the magnitude of the influent flow to the reactor and said set point.
Claim 8
Independent Claim
105 words
A system for controlling the pX of the effluent from a process reactor at a predetermined set point by linearly varying the reagent flow to the reactor in response to a final control signal comprising, means for producing a feedforward control signal in response to the pX of the influent, means for producing a feedback control signal in proportion to the deviation of tHe pX of the effluent from its set point and the integral of said deviation, and means for summing said feedforward control signal with the product of said feedforward control signal and said feedback control signal to produce said final control signal.
Claim 9
Independent Claim
156 words
A system for controlling the pX of the effluent from a process reactor at a predetermined set point by linearly varying the reagent flow to the reactor in response to a final control signal comprising: means for producing a feedforward control signal in response to the magnitude of the influent flow to the reactor, the pX of the influent, and said set point, means for producing a feedback control signal in accordance with the deviation of the pX of the effluent from said set point, and means for combining said feedforward control signal and said feedback control signal to produce said final control signal as a function of the product of said feedforward control signal and said feedback control signal, said function of the product of said feedforward control signal and said feedback control signal including the sum of the feedforward control signal and the product of the feedforward control signal and the feedback control signal.
Claim 10
Dependent Claim
37 words
A system as set forth in claim 10 in which the means for producing a feedback control signal has both proportional and reset response to the deviation of the pX of the effluent from its set point.
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) | 1977-02-11 | 1977-08-13 | 1978-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-11 | 1981-08-13 | 1982-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-11 | 1985-08-13 | 1986-02-12 | $7700.00 | Window Closed / Lapsed |