Patent US3781533A successfully refreshed from Google Patents.
US3781533A
Expired / Lapsed
US
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Constraint control system for optimizing performance of process units
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1972-04-07
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Granted: 1973-12-25
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Expires: 1992-04-07
Abstract
Abstract A control system which automatically optimizes the performance of a process unit by continuously scanning the important operating variables, measuring the deviation of these variables from a preselected target, identifying the instant limiting variable, calculating the change in a manipulated variable required to bring the most limiting variable to its target, adjusting the manipulated variable to make the calculated change, correcting operating conditions outside the control system to relieve the instant limit, and repeating the control process to identify a new limiting variable and to make changes needed to bring the new limiting variable to its target.
Inventors
- 👤 L Barnstone
- 👤 R Levy
- 👤 S Morris
- 👤 R Bartman
- 👤 A Lopez
- 👤 H Mosler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:21
CPC Classifications
B; B01; B01D; B01D3/00; B01D3/42; B01D3/4211; B01D3/425; B01J; B01J19/00; B01J19/0006; B01J19/0033; Y; Y10; Y10S; Y10S208/00; Y10S208/01
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
89 words
A method for controlling a process operating under supervision of a multiplicity of feedback control loops comprising in combination: a. monitoring the instant operation of each of a group of preselected variables; b. determining the deviation of each said variable from its predetermined target value; c. selecting the limiting one of the deviations determined in (b), said limiting deviation being the one which permits the most restrictive change in a preselected manipulated variable; d. adjusting a preselected manipulated variable to cause said limiting deviation to become equal to zero.
Claim 2
Independent Claim
89 words
A method for controlling a process operating under supervision of a multiplicity of feedback control loops comprising in combination: a. monitoring the instant operation of each of a group of preselected variables; b. determining the deviation of each said variable from its predetermined target value; c. selecting the limiting one of the deviations determined in (b), said limiting deviation being the one which permits the most restrictive change in a preselected manipulated variable; d. adjusting a preselected manipulated variable to cause said limiting deviation to become equal to zero.
Claim 3
Independent Claim
123 words
A method for controlling a process operating under supervision of a multiplicity of feedback control loops comprising in combination the steps of: a. selecting variables to be monitored; b. establishing target values for said monitored variables; c. determining the constraint sensitivity of each of said variables to a preselected manipulated variable; d. monitoring said variables; e. determining the instant deviation of each of said variables from its respective target value; f. dividing the instant deviation of each of said variables by its constraint sensitivity determined in (c), thereby obtaining the constraint deviation of each variable. g. comparing the instant constraint deviations of said variables and selecting as a key constraint deviation that which permits the most restrictive change in a preselected manipulated variable.
Claim 4
Independent Claim
123 words
A method for controlling a process operating under supervision of a multiplicity of feedback control loops comprising in combination the steps of: a. selecting variables to be monitored; b. establishing target values for said monitored variables; c. determining the constraint sensitivity of each of said variables to a preselected manipulated variable; d. monitoring said variables; e. determining the instant deviation of each of said variables from its respective target value; f. dividing the instant deviation of each of said variables by its constraint sensitivity determined in (c), thereby obtaining the constraint deviation of each variable. g. comparing the instant constraint deviations of said variables and selecting as a key constraint deviation that which permits the most restrictive change in a preselected manipulated variable.
Claim 5
Dependent Claim
58 words
The method of claim 2, further comprising the steps of: h. determining the difference between said most restrictive constraint deviation and zero; i. adjusting said preselected manipulated variable by means of an associated feedback controller loop; j. repeating steps (d) through (i) until the most restrictive constraint deviation reaches zero, whereupon said process has reached a constrained condition.
Claim 6
Dependent Claim
22 words
The process of claim 2 wherein the most restrictive change of a preselected manipulated variable is one having the least numerical value.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |