Time delay algorithms for control of rolling mills

Abstract

In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness and to make the thickness uniform. The final thickness of the strip is measured at a little downstream from the roll gap where the deflection of strip happens. In other words, there is an unavoidable non-negligible transport delay in the measurement of steel strip thickness. Furthermore, there exists a periodic disturbance signal in rolling mills. In this master thesis two control approaches, namely internal model control and repetitive control are designed and numerically simulated in MATLAB Simulink to compensate this delay and eccentricity in rolling mills.In metalworking, rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness and to make the thickness uniform. The final thickness of the strip is measured at a little downstream from the roll gap where the deflection of strip happens. In other words, there is an unavoidable non-negligible transport delay in the measurement of steel strip thickness. Furthermore, there exists a periodic disturbance signal in rolling mills. In this master thesis two control approaches, namely internal model control and repetitive control are designed and numerically simulated in MATLAB Simulink to compensate this delay and eccentricity in rolling mills.