Method of controlling transverse shape of rolled strip, based on tension distribution

A method of controlling a transverse shape of a strip rolled by a rolling mill having a pair of work rolls, equipped with a plurality of shape correcting devices for correcting the shape of the rolled strip in the direction of width thereof, said shape correcting devices being associated with said work rolls, said devices including a tilt adjusting device, a work roll bending force adjusting device, and a bending force differential adjusting device, said method comprising the steps of:

• detecting a change in a rolling force acting on said strip;
• detecting a tension distribution of the rolled strip in said direction of width of the strip, immediately after the rolling of the strip;
• calculating a strain distribution of said rolled strip in said direction of width, on the basis of the detected tension distribution;
• calculating from the calculated strain distribution, a shape parameter which represents a shape error of said rolled strip;
• estimating, on the basis of the detected change in the rolling force and the calculated shape parameter, first, second and third disturbance values of said rolling mill which should be zeroed by said tilt adjusting device, said bending force differential adjusting device and said work roll bending force adjusting device, respectively, said first, second and third disturbance values being estimated according to the equation (46), (51) and (59) identified in the specification, respectively, so as to offset a delay in the detection of said tension distribution which is reflected on said shape parameter, each of said equations (46), (51) and (59) including a value for offsetting said delay in the detection of said tension distribution, and a value relating to a response characteristic of a corresponding one of said tilt adjusting device, said bending force differential adjusting device and said work roll bending force adjusting device;
• and
• controlling said shape correcting devices, according to the estimated first, second and third disturbance values, without an influence of said delay in the detection of said tension distribution.