US3704609A
Expired / Lapsed
US
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Rolling mill gauge control during acceleration
Assignee: Westinghouse Electric Corp
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Filing: 1971-06-25
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Granted: 1972-12-05
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Expires: 1991-06-25
Abstract
Abstract Rolling mill control system for controlling the output gauge of strip material being rolled during acceleration of the mill. This is accomplished by utilizing feed-forward computer techniques to anticipate changes in mill variables and to regulate those variables to maintain constant output gauge during acceleration. Feedback techniques are then used to trim-up the control system, to update the predictive model equations and to dynamically control gauge during acceleration.
Inventors
- 👤 John D Sterret Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:58
CPC Classifications
B; B21; B21B; B21B37/00; B21B37/58; B21B37/60
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
105 words
In the method for controlling the gauge of strip material issuing from a rolling mill during acceleration of the mill; the steps of generating a feedforward predictive electrical signal proportional to the rate of change of a mill variable necessary to maintain constant output gauge from a consideration of the acceleration rate of the mill, generating a feedback electrical signal proportional to the rate of change of said mill variable from a consideration of variation in actual output gauge from a desired constant output gauge, and controlling said mill variable to maintain output gauge constant from a consideration of both said feed-forward and feedback signals.
Claim 2
Dependent Claim
105 words
In the method for controlling the gauge of strip material issuing from a rolling mill during acceleration of the mill; the steps of generating a feedforward predictive electrical signal proportional to the rate of change of a mill variable necessary to maintain constant output gauge from a consideration of the acceleration rate of the mill, generating a feedback electrical signal proportional to the rate of change of said mill variable from a consideration of variation in actual output gauge from a desired constant output gauge, and controlling said mill variable to maintain output gauge constant from a consideration of both said feed-forward and feedback signals.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein said mill variable is controlled by an electrical signal proportional to the sum of said feedforward and feedback signals.
Claim 4
Dependent Claim
17 words
The method of claim 1 wherein said mill variable comprises the speed of a screwdown drive motor.
Claim 5
Dependent Claim
60 words
The method of claim 1 wherein said mill variable comprises the speed of a screwdown drive motor for the mill and wherein said feedforward predictive electrical signal is derived by computing the desired present screw position and subtracting the present desired screw position from the calculated desired screw position existing a time interval before, and dividing by said time interval.
Claim 6
Dependent Claim
62 words
The method of claim 1 wherein said mill variable comprises the speed of a screwdown drive motor for the mill and wherein said feedforward predictive electrical signal is derived by calculating: where V0 speed of the mill at the start of acceleration, a acceleration rate of the mill, t elapsed time following the start of acceleration, and K7 and K5 are constants.
Claim 7
Dependent Claim
52 words
The method of claim 1 wherein said feedback electrical signal is calculated from: Kb X Dn X Delta Fn where Kb is a constant, Dn is the mill spring constant, and Delta Fn is the difference in roll force between one calculation and the calculation taken a time period Delta t before.
Claim 8
Dependent Claim
20 words
The method of claim 6 wherein said feedback electrical signal is calculated each time the time period Delta t elapses.
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) | 1975-12-05 | 1976-06-05 | 1976-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-05 | 1980-06-05 | 1980-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-05 | 1984-06-05 | 1984-12-05 | $7700.00 | Window Closed / Lapsed |