Rolling mill gauge control system
OwnerThomas J. Alshukinventor
Life of this patent
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Abstract
An automatic gauge control system for screwdown adjustment of a cold rolling mill using separate feed-forward and feed-backward screwdown adjustments and wherein the feed-backward screwdown adjustment is based on the difference between a short term output gauge average and an input gauge rolling average which is adaptively modified with a statistical analysis of output gauge variations and wherein the feed-forward screwdown adjustment is based on a net weighted iput gauge variation adaptively controlled in accordance with a statistical analysis of input and output gauge variations.
Claims16
A gauge control system for a rolling mill having at least one mill stand with an adjustable screwdown for controlling the roll opening thereof through which a sheet metal workpiece is fed during a rolling mill run for reducing the thickness of the workpiece from an input gauge to an output gauge, screwdown adjustment means for adjusting the mill stand screwdown and thereby to adjust the roll opening and workpiece output gauge, means for measuring the input gauge (G.sub.I) of each of a plurality of successive samples of the sheet metal workpiece to provide a rolling queue of a plurality of successive incremental gauge variations (.DELTA.G.sub.I) for a plurality of successive sheet metal samples approaching the rolling mill;
- and computing means employing a predetermined mill screwdown adjustment model for determining any corrective incremental screwdown adjustment for each successive sheet metal sample for achieving a desired output gauge (G.sub.NO) and employing a net weighted input gauge variation (.DELTA.G.sub.WI) which is equal to a summation of said plurality of successive incremental gauge variations (.DELTA.G.sub.I) successively weighted with successively decreasing weightings, the screwdown adjustment means being connected to be operated by the computing means for incrementally adjusting the mill screwdown for each successive sheet metal sample in accordance with any corrective incremental screwdown adjustment determined by said computing means, and said computing means being operable for adaptively adjusting said successively decreasing weightings, thereby to adaptively adjust the net weighted input gauge variation (.DELTA.G.sub.WI).
A gauge control system for a rolling mill having at least one mill stand with an adjustable screwdown for controlling the roll opening thereof through which a sheet metal workpiece is fed during a rolling mill run for reducing the thickness of the workpiece from an input gauge to an output gauge, screwdown adjustment means for adjusting the mill stand screwdown and thereby to adjust the roll opening and workpiece output gauge, means for measuring the input gauge (G.sub.I) of each of a plurality of successive samples of the sheet metal workpiece to provide a rolling queue of a plurality of successive incremental gauge variations (.DELTA.G.sub.I) for a plurality of successive sheet metal samples approaching the rolling mill and for measuring the output gauge (G.sub.O) of corresponding sheet metal samples leaving the rolling mill, and computing means employing a predetermined mill screwdown adjustment model for determining separate feed-forward and feed-backward corrective incremental screwdown adjustments for achieving a desired output gauge (G.sub.NO) and using rolling mill variables consisting primarily of the measured input gauge (G.sub.I) and the measured output gauge (G.sub.O) and with the feed-forward screwdown adjustments being based primarily on said gauge variations (.DELTA.G.sub.I) and the feed-backward screwdown adjustments being based primarily on an input gauge rolling average (G.sub.AI) and variations between selected output gauge averages (G.sub.SO) respectively and the desired output gauge (G.sub.NO), the screwdown adjustment means being connected to be operated by the computing means for incrementally adjusting the mill screwdown in accordance with any corrective incremental screwdown adjustment determined by said computing means.
A gauge control system for a rolling mill having at least one mill stand with an adjustable screwdown for controlling the roll opening thereof through which a sheet metal workpiece is fed during a rolling mill run for reducing the thickness of the workpiece from an input gauge to an output gauge, screwdown adjustment means for adjusting the mill stand screwdown and thereby to adjust the roll opening and workpiece output gauge, means for measuring the input gauge (G.sub.I) of each of a plurality of successive samples of the sheet metal workpiece as they approach the rolling mill and for measuring the output gauge (G.sub.O) of corresponding samples of the sheet metal workpiece after they leave the rolling mill, and computing means employing a predetermined mill screwdown adjustment model for determining any corrective screwdown adjustment for achieving a desired output gauge (G.sub.NO) and using rolling mill running variables consisting primarily of the measured input gauge (G.sub.I) and the measured output gauge (G.sub.O), and determining feed-backward screwdown adjustments based essentially on selected output gauge averages (G.sub.SO) and a calculated input gauge (G.sub.CI) calculated from an input gauge rolling average (G.sub.AI) and adaptively adjusted during the rolling mill run, the screwdown adjustment means being connected to be operated by the computing means for incrementally adjusting the mill screwdown in accordance with any corrective incremental screwdown adjustment determined by said computing means.
A method of providing output gauge control of a rolling mill having at least one mill stand with an adjustable screwdown for controlling the roll opening thereof through which a sheet metal workpiece is fed during a rolling mill run for reducing the thickness of the workpiece from an input gauge to an output gauge, comprising the steps of measuring the input gauge (G.sub.I) of each of a plurality of successive samples of the sheet metal workpiece to provide a rolling queue of a plurality of successive incremental gauge variations (.DELTA.G.sub.I) for a plurality of successive sheet metal samples approaching the rolling mill and measuring the output gauge (G.sub.O) of corresponding sheet metal samples leaving the rolling mill, using computing means for determining corrective incremental screwdown adjustments for achieving a desired output gauge (G.sub.NO) by employing a predetermined mill screwdown adjustment model using rolling mill running variables comprising measured input gauge (G.sub.I) and measured output gauge (G.sub.O), a net weighted input gauge variation (.DELTA.G.sub.WI) which is equal to a summation of said plurality of successive incremental gauge variations (.DELTA.G.sub.I) successively weighted with successively decreasing weightings, a selected output gauge average (G.sub.SO) and an input gauge rolling average (G.sub.AI) and by determining separate corrective feed-forward and feed-backwark incremental screwdown adjustments (.DELTA.SD.sub.F) and (.DELTA.SD.sub.B) respectively by employing said net weighted input gauge variation (.DELTA.G.sub.WI) to determine a feed-forward adjustment (.DELTA.SD.sub.F) and by employing said input gauge rolling average (G.sub.AI) and said selected output gauge average (G.sub.SO) to determine a feed-back adjustment (.DELTA.SD.sub.B), and adjusting the mill screw-down in accordance with said separate corrective feed-forward and feed-backward incremental screwdown adjustments determined by the computing means.
A method of providing output gauge control of a rolling mill having at least one mill stand with an adjustable screwdown for controlling the roll opening thereof through which a sheet metal workpiece is fed during a rolling mill run for reducing the thickness of the workpiece from an input gauge to an output gauge, comprising the steps of measuring the input gauge (G.sub.I) of each of a plurality of successive samples of the sheet metal workpiece as they approach the rolling mill, measuring the output gauge (G.sub.O) of corresponding sheet metal samples leaving the rolling mill, using computing means for determining corrective incremental screwdown adjustments for achieving a desired output gauge (C.sub.NO) by employing a predetermined mill screwdown adjustment model using rolling mill running variables comprising primarily measured input gauge (G.sub.I) and measured output gauge (G.sub.O), and by determining separate corrective feed-forward and feed-backward incremental screwdown adjustments (.DELTA.SD.sub.F) and (.DELTA.SD.sub.B) respectively by employing an input gauge variation (.DELTA.G.sub.WI) which is based on a plurality of successive incremental gauge variations (.DELTA.G.sub.I) to determine a feed-forward adjustment (.DELTA.SD.sub.F) and by employing an input gauge average (G.sub.AI) based on the measured input gauge (G.sub.I) and an output gauge average (G.sub.SO) based on the measured output gauge (G.sub.O) to determine a feed-back adjustment (.DELTA.SD.sub.B), and adjusting the mill screwdown in accordance with said separate corrective feed-forward and feed-backward incremental screwdown adjustments determined by the computing means.
A method of providing output gauge control of a rolling mill having at least one mill stand with an adjustable screwdown for controlling the roll opening thereof through which a sheet metal workpiece is fed during a rolling mill run for reducing the thickness of the workpiece from an input gauge to an output gauge, comprising the step of measuring the input gauge (G.sub.I) of each of a plurality of successive samples of the sheet metal workpiece as they approach the rolling mill, measuring the output gauge (G.sub.O) of corresponding sheet metal samples leaving the rolling mill, using computing means for determining corrective incremental screwdown adjustments for achieving a desired output gauge (G.sub.NO) by employing a predetermined mill screwdown adjustment model using rolling mill running variables comprising primarily measured input gauge (G.sub.I) and measured output gauge (G.sub.O), and by determining feed-backward incremental screwdown adjustments (.DELTA.SD.sub.B) by employing an input gauge average (G.sub.AI) and an output gauge average (G.sub.SO), and adjusting the mill screwdown in accordance with said feed-backward incremental screwdown adjustments determined by the computing means.
A method of providing output gauge control of a rolling mill having at least one mill stand with an adjustable screwdown for controlling the roll opening thereof through which a sheet metal workpiece is fed during a rolling mill run for reducing the thickness of the workpiece from an input gauge to an output gauge, comprising the step of measuring the input gauge (G.sub.I) of each of a plurality of successive samples of the sheet metal workpiece to provide a rolling queue of a plurality of successive incremental gauge variations (.DELTA.G.sub.I) for a plurality of successive sheet metal samples approaching the rolling mill and measuring the output gauge (G.sub.O) of corresponding sheet metal samples leaving the rolling mill, using computing means for determining corrective incremental screwdown adjustments for achieving a desired output gauge (G.sub.NO) by employing a predetermined mill screwdown adjustment model using a net weighted input gauge variation (.DELTA.G.sub.WI) which is equal to a summation of said plurality of successive incremental gauge variations (.DELTA.G.sub.I) successively weighted with successively decreasing weightings and by determining corrective feed-forward incremental screwdown adjustments (.DELTA.SD.sub.F) from said net weighted input gauge variations (.DELTA.G.sub.WI), adjusting the mill screwdown in accordance with said corrective feed-forward incremental screwdown adjustments determined by the computing means, and automatically adaptively controlling the feed-forward incremental screwdown adjustments by adaptively adjusting said successive weightings by statistical analysis of the measured output gauge (G.sub.O).
Dependencies are inferred from the claim text.