US3787667A
Expired / Lapsed
US
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Computer controlled metal rolling mill
Assignee: General Electric Co
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Filing: 1971-01-06
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Granted: 1974-01-22
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Expires: 1991-01-06
Abstract
Abstract A computer controlled cold metal rolling mill is described wherein force and power curves stored within a calculated set-up model are adapted in response to sensed on-line rolling conditions to optimize power distribution between stands of the mill. For maximum storage capacity and simplification of the adaptive feedback calculations, the power curves are stored in the set-up model by two numerals representing the slope and base of a graph of power per unit volume flow against elongation as plotted on log log-log scales. Thus, only the slope and base of the actual power curve need be calculated during operation to modify the power curves stored within the set-up model. Adaptation of the force curves within the model is accomplished in association with feedback logic for adjusting the value of the coefficient of friction (assumed for calculation of force) by an amount proportional to the difference between the observed and calculated force. Both fast and slow feedback terms are employed for this purpose with the fast feedback term approaching zero asymptotically as the slow feedback term approaches a coefficient of friction equating the measured and predicted forces. Integral scanning and comparison also are utilized to evaluate the quality of adaptive data before updating the stored curves. Also disclosed is the storage of mill stretch curves as functions of roll force against mill stretch for nominal constant roll force per unit width with a modifier being employed to correct for variations in force per unit width from nominal.
Inventors
- 👤 W King
- 👤 A Winchester
- 👤 G Larson
- 👤 D Steeper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:31
CPC Classifications
B; B21; B21B; B21B37/00; B21B37/16
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
169 words
In a method of rolling metal of known composition from a first thickness to a second thickness within a plurality of tandem rolling stands by storing within a computer memory empirically determined power information corresponding to diverse metals to be rolled, proportioning the power requirements for each rolling stand from the stored power information for the rolled metal and adaptively up-dating the power information by feeding back to the computer measured parameters indicative of the actual power utilized during rolling, the improvement comprising employing data representing a plot of variables depicting the relationship between power per unit volume flow against elongation on a log log-log scale to provide a linear relationship between the plot of variables, calculating the slope and intercept of the linear relationship, storing the power information in the computer by indicia representing the slope and intercept of the linear relationship and accessing the stored slope and intercept indicia to obtain process parameters utilized to adjust the rolling stands and thereby control the rolling of the metal.
Claim 2
Dependent Claim
169 words
In a method of rolling metal of known composition from a first thickness to a second thickness within a plurality of tandem rolling stands by storing within a computer memory empirically determined power information corresponding to diverse metals to be rolled, proportioning the power requirements for each rolling stand from the stored power information for the rolled metal and adaptively up-dating the power information by feeding back to the computer measured parameters indicative of the actual power utilized during rolling, the improvement comprising employing data representing a plot of variables depicting the relationship between power per unit volume flow against elongation on a log log-log scale to provide a linear relationship between the plot of variables, calculating the slope and intercept of the linear relationship, storing the power information in the computer by indicia representing the slope and intercept of the linear relationship and accessing the stored slope and intercept indicia to obtain process parameters utilized to adjust the rolling stands and thereby control the rolling of the metal.
Claim 3
Dependent Claim
45 words
The method of rolling metal according to claim 1 further including converting, in said computer, the data representing the plot of variables depicting the relationship on a log log-log scale to data representing linear co-ordinates to be utilized in proportioning the power requirements between stands.
Claim 4
Dependent Claim
117 words
The method of rolling metal according to claim 1 further including calculating in the computer the relationship between power per unit volume flow and elongation from parameters observed during actual rolling of metal, determining the slope and intercept of a straight line passing through the power per unit volume flow relationship and adapting the stored power information to the calculated relationships by electrically comparing the slopes and intercepts of the stored information and the straight line and altering the stored slope and intercept by an amount proportional to the difference in the slopes and intercepts, respectively, of the straight line and the stored information whereby the stored power information is up-dated in accordance with the observed parameters.
Claim 5
Dependent Claim
125 words
The method of rolling metal of known composition from a first thickness to a second thickness according to claim 1 further including measuring a chosen process variable during on-line operation, electrically calculating in the computer the chosen variable from both actually sensed and assumed process parameters having a known relationship to said chosen variable, comparing said calculated variable with the measured variable and adjusting the assumed parameter upon a deviation between the measured and the calculated variables, said adjustment being accomplished by performing a dual integration function with respect to a signal proportional to the deviation, the two integration functions being performed using integration constants, and summing the output results of said dual integration function to obtain the total cumulative correction for said assumed parameter.
Claim 6
Dependent Claim
119 words
A method of rolling metal of known composition from a first thickness to a second thickness according to claim 1 further including storing within a computer memory information defining the relationship between rolling force and mill stretch for a single rolling force per unit width of metal being rolled, electrically calculating in the computer the actual force per unit width of metal at a rolling stand, modifying in the computer the stretch calculated from the stored information by an amount proportional to the variation between the actual rolling force per unit width and the rolling force per unit width of the stored information and adjusting the rolling force at a stand by an amount dependent upon the modified stretch.
Claim 7
Dependent Claim
162 words
In a method of rolling metal sheet of diverse composition and width to effect a change in the sheet thickness from a first thickness to a second thickness within a plurality of tandem rolling stands each having a controlled roll positioner to regulate the rolling force applied to the metal sheet at the stand by adaptively up-dating predetermined stored data, the improvement comprising storing within a computer memory information defining the relationship between rolling force and mill stretch for a single rolling force per unit width of metal sheet, calculating in the computer the rolling force per unit width of metal sheet at a rolling stand, modifying the stretch calculated from the stored information by an amount proportional to the difference in the actual rolling force per unit width and the force per unit width of the stored information and adjusting the rolling force at a particular stand by an amount dependent upon the rolling force as determined from the modified stretch.
Claim 8
Dependent Claim
162 words
In a method of rolling metal sheet of diverse composition and width to effect a change in the sheet thickness from a first thickness to a second thickness within a plurality of tandem rolling stands each having a controlled roll positioner to regulate the rolling force applied to the metal sheet at the stand by adaptively up-dating predetermined stored data, the improvement comprising storing within a computer memory information defining the relationship between rolling force and mill stretch for a single rolling force per unit width of metal sheet, calculating in the computer the rolling force per unit width of metal sheet at a rolling stand, modifying the stretch calculated from the stored information by an amount proportional to the difference in the actual rolling force per unit width and the force per unit width of the stored information and adjusting the rolling force at a particular stand by an amount dependent upon the rolling force as determined from the modified stretch.
Claim 9
Dependent Claim
177 words
In a method of rolling metal to effect a reduction in metal thickness from a first thickness to a second thickness wherein a critical process variable is measured during on-line operation and compared in a computer to a value of the variable as calculated from both actually sensed and assumed process parameters having known relationships to said variable, the improvement comprising adjusting said assumed parameter upon a deviation between the measured and the calculated critical process variables by an amount proportional to the deviation utilizing a dual integration function wherein each integration function has a different gain to generate output terms, said adjusting being accomplished by feeding the output term derived from the higher gain integration function as an input signal to the lower gain integration function, electrically summing the output terms of the dual integration functions to obtain a cumulative correction for said assumed parameter, and readjusting said assumed process parameter through the dual integration functions by an amount proportional to the deviation between the measured variable and the calculated variable utilizing the corrected assumed parameter.
Claim 10
Dependent Claim
177 words
In a method of rolling metal to effect a reduction in metal thickness from a first thickness to a second thickness wherein a critical process variable is measured during on-line operation and compared in a computer to a value of the variable as calculated from both actually sensed and assumed process parameters having known relationships to said variable, the improvement comprising adjusting said assumed parameter upon a deviation between the measured and the calculated critical process variables by an amount proportional to the deviation utilizing a dual integration function wherein each integration function has a different gain to generate output terms, said adjusting being accomplished by feeding the output term derived from the higher gain integration function as an input signal to the lower gain integration function, electrically summing the output terms of the dual integration functions to obtain a cumulative correction for said assumed parameter, and readjusting said assumed process parameter through the dual integration functions by an amount proportional to the deviation between the measured variable and the calculated variable utilizing the corrected assumed parameter.
References Cited (Backward Citations)
US26996A
Cited
US3634662A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |