Dynamic roll eccentricity identification using extended Kalman filter state estimation and control upgrade for cold rolling mills

A method of programming a controller for controlling a thickness of a sheet metal produced by a rolling mill stand, the rolling mill stand comprising a first work roll and a second work roll respectively positioned between a first back up roll and a second back up roll, the method comprising:

• receiving an input comprising at least a plurality of parameters associated with the thickness of the sheet metal and the rolling mill stand;
• generating a model of the rolling mill stand based on the plurality of parameters;
• estimating, using the model, an eccentricity in the rolling mill stand based on feedback input from the rolling mill stand in run time, wherein the feedback input comprises at least angular velocities of the first back up roll and the second back up roll, a roll force, and an average gap between the first work roll and the second work roll;
• estimating, by a filter, a state of the rolling mill stand based on at least the estimated eccentricity and the model of the rolling mill stand;
• and
• generating an output including a roll eccentricity compensation signal based on at least the estimated state of the rolling mill stand to control a gap between the first work roll and the second work roll for controlling the thickness of the sheet metal produced by the rolling mill stand.

A metal rolling mill system for controlling thickness of sheet metal, the metal rolling mill system comprising:

• a rolling mill stand comprising a first work roll and a second work roll respectively positioned between a first back up roll and a second back up roll;
• a processor;
• one or more sensors configured to measure a plurality of parameters associated with the thickness of the sheet metal and the rolling mill stand;
• and
• a memory device coupled to the processor and comprising a readable program for execution by the processor to:
• receive an input comprising the plurality of parameters from the one or more sensors;
• generate a model of the rolling mill stand based on the plurality of parameters;
• estimate, using the model, an eccentricity in the rolling mill stand based on feedback input measured from the rolling mill stand in run time, wherein the feedback input comprises at least angular velocities of the first back up roll and the second back up roll, a roll force, and an average gap between the first work roll and the second work roll;
• estimate, by a filter, a state of the rolling mill stand based on at least the estimated eccentricity and the model of the rolling mill stand;
• and
• generate an output including a roll eccentricity compensation signal based on at least the estimated state of the rolling mill stand to control a roll gap between the first work roll and the second work roll for controlling the thickness of the sheet metal produced by the rolling mill stand.