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

Abstract

Control system for cold rolling mills to improve sheet metal thickness uniformity. Sensors monitor the state of the cold rolling mill by measuring (i) roll eccentricity, (ii) roll slips during mill operation, (iii) mill disturbances from roll speed or roll force manifestations, and (iv) unknown disturbances referred to as process noise. The controller analyzes data from sensors to compensate. Data collected during the mill operation by the sensors are delayed in reaching the controller. This communication delay is accounted for by using a filter. Since an objective of the controller software is dynamic identification of eccentricity of the back up rolls, which is non-linear by nature, an Extended Kalman Filter may be used.