US3838256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constraint control for processes with equipment limitations
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1973-12-03
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Granted: 1974-09-24
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Expires: 1993-12-03
Abstract
Abstract In a constraint control system which automatically optimizes the performance of a process unit by continuously scanning important operating variables, measuring the deviation of those variables from their preselected target values, identifying the instant limiting variable, and adjusting a predetermined manipulated variable to bring the limiting variable to its target value, when one of the operating variables exceeds its target value and is an equipment limitation, the error signal is augmented to indicate the true extent of the deviation which must be corrected in order to bring that variable back to its target value.
Inventors
- 👤 H Mosler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:06
CPC Classifications
G; G05; G05B; G05B13/00; G05B13/02; Y; Y10; Y10S; Y10S208/00; Y10S208/01
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
163 words
In a constraint control system for controlling the performance of processes in which instant values of preselected operating variables are measured, the deviation of said instant values from their predetected target values is determined, the instant limiting variable is identified as the one requiring the most restrictive change to a predetermined manipulated variable and an adjustment is made to said predetermined manipulated variable to bring the limiting variable to its target value, wherein the improvement comprises: when said operating variable is an equipment position which is automatically controlled relative to the deviation process of a measuremeNt from the set point of the associated controller and said operating variable is subject to a hard constraint which cannot be exceeded and which prevents its indicating the correct deviation of said variable from its target value, augmenting the instant deviation of said operating variable in order to make said instant deviation reflect the deviation of said process measurement from the set point of the associated controller.
Claim 2
Dependent Claim
163 words
In a constraint control system for controlling the performance of processes in which instant values of preselected operating variables are measured, the deviation of said instant values from their predetected target values is determined, the instant limiting variable is identified as the one requiring the most restrictive change to a predetermined manipulated variable and an adjustment is made to said predetermined manipulated variable to bring the limiting variable to its target value, wherein the improvement comprises: when said operating variable is an equipment position which is automatically controlled relative to the deviation process of a measuremeNt from the set point of the associated controller and said operating variable is subject to a hard constraint which cannot be exceeded and which prevents its indicating the correct deviation of said variable from its target value, augmenting the instant deviation of said operating variable in order to make said instant deviation reflect the deviation of said process measurement from the set point of the associated controller.
Claim 3
Dependent Claim
47 words
The constraint control system of claim 1 wherein said augmentation of the instant deviation of said operating variable from its target value consists of adding to said instant deviation a value proportional to the difference between said process measurement and the set point of the associated controller.
References Cited (Backward Citations)
US3665493A
Cited
US3761690A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-23 | 1978-03-25 | 1978-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-23 | 1982-03-25 | 1982-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-23 | 1986-03-25 | 1986-09-24 | $7700.00 | Window Closed / Lapsed |