Apparatus and method for adaptive control of a rolling mill

A rolling mill for controllinq a velocity dependent factor of strip material being processed in the mill, comprising:

• (a) input means for supplying strip material;
• (b) first and second spaced work rolls downstream of said input means for processing strip material passing therebetween;
• (c) means for adjusting the spacing between said work rolls;
• (d) output means downstream of said work rolls for removing processed material;
• (e) first tachometer means operably associated with said input means for determining the apparent velocity of the material thereat, second tachometer means operably associated With one of said work rolls for determining the apparent velocity of the material passing between said work rolls, and third tachometer means operably associated with said output means for determining the apparent velocity of the material thereat;
• (f) slip determining means operably associated with said first, second and third tachometer means for determining input slip by comparing the apparent input velocity with the apparent work roll velocity and for determining output slip by comparing the apparent output velocity with the apparent work roll velocity;
• (g) first means operably associated with said slip determining means for calculating a velocity dependent factor when input slip exceeds output slip and for calculating a first derived factor when the calculated factor exceeds a previously calculated factor by more than the selected amount and for calculating a first adaptive parameter used to calculate the first derived factor when the calculated factor is less than the previously calculated factor by less than the selected amount;
• (h) second means operably associated with said slip determining means for calculating the velocity dependent factor when the output slip exceeds or is equal to the input slip and for calculating a second derived factor when the calculated factor exceeds the previously calculated factor by more than a selected amount and for calculating a second adaptive parameter used for calculating the second derived factor when the calculated factor is less than the previously calculated factor by less than the selected amount;
• (i) averaging means operably associated with said first and second means for calculating an averaged velocity dependent factor from a selected number of calculated and/or derived factors;
• (j) error determining means operably associated with said averaging means for computing an error factor by comparing the averaged velocity factor with a target factor;
• and,
• (k) control means operably associated with said error determining means and with said adjusting means for causing regulation of the spacing between said work rolls in response to the error factor.

The method of controlling a velocity dependent factor of strip material being processed in a mill having an input assembly supplying material to be processed, spaced work rolls for processing the material, means for adjusting the spacing between the work rolls, and an output assembly for removing processed material, the method comprising the steps of:

• (a) simultaneously determining the apparent velocity of material prior to, between and subsequent to the work rolls;
• (b) determining input slip by comparing the apparent input Velocity with the apparent work roll velocity and determining output slip by comparing the apparent output velocity with the apparent work roll velocity;
• (c) calculating a selected velocity dependent factor in response to a comparison of input slip with output slip;
• (d) comparing the calculated factor with a previously calculated factor and calculating a derived factor when the calculated factor exceeds the previously calculated factor by more than a selected amount and calculating an adaptive factor used to calculate the derived factor when the calculated factor does not exceed the preceding calculated factor by the selected amount;
• (e) averaging a selected number of the calculated and/or derived factors;
• (f) determining the divergence between the averaged factor and a target factor;
• and,
• (g) adjusting the spacing between the work rolls in response to the divergence of the averaged factor with the target factor.

Apparatus for regulating the operation of a rolling mill having a material input, opposed work rolls, means for adjusting the spacing between the work rolls, and a material output, the apparatus comprising:

• (a) means for determining slip at the inlet and the outlet;
• (b) means for calculating a velocity dependent factor based upon the velocity of the material at the output and the input;
• (c) means for comparing the calculated factor with an aim factor;
• (d) means for calculating a derived factor when the calculated factor exceeds a previously calculated factor by more than a selected amount and for calculating an adaptive factor used to calculate the derived factor when the calculated factor does not exceed the previously calculated factor by more than the selected amount;
• (e) means for generating an averaged factor from a selected number of calculated and/or derived factors;
• (f) means for determining the divergence of the averaged factor with an aim factor;
• and,
• (g) means for operably association with the adjusting means for causing regulation of the spacing between the work rolls in response to the divergence determined.