Patent ID: 7748247
Filing Date: 2010-07-06
Classification: B21B

Abstract:
1. A process for regulating flatness of a metal strip at an output from a roll stand including means for regulating flatness including at least one dynamic flatness actuator, the method comprising: characterizing, during rolling, the flatness of the strip by measurement of a quantity D at n points distributed over the width of the strip, based on n measurements of the quantity D; determining, using a model of an effect on flatness of regulation of flatness and an optimization method, an overall set-point for the regulating means, the overall set-point including at least one elementary set-point for a dynamic actuator, so that a calculated residual flatness error criterion is minimal, and the overall set-point is implemented by the means for regulating flatness, wherein the model of effect on flatness used to determine the overall set-point includes, for each dynamic actuator, as many submodels as there are points of measurement of the quantity D characteristic of flatness, each submodel making it possible to calculate the effect on the quantity D, at a relevant point, of a relevant dynamic actuator when a setpoint is applied to it; and wherein the calculated residual flatness error criterion is a linear combination of the quadratic difference and the maximum amplitude of the difference between the calculated residual error and a target error.