Optical Gauge Control - the latest method of controlling gauge to precise tolerances

摘要

OGC - Optical Gauge Control has been developed by MDM for aluminium hot mill applications and is the latest method of controlling gauge to precise tolerances. The system utilises optical sensors located at the operator and the drive side of the mill for establishing the position of the top back-up roll. This allows the offset of the top back-up roll to be measured to an absolute value when compared to a static benchmark within the mill foundation. The components of mill stretch can in consequence be excluded and the roll gap geometry accurately calculated from the measured value by considering roll diameters, thermal crown and roll flattening. From a control engineering point of view this approach leads to stiffer mill stand behaviour and improved and more dynamic control response to roll gap changes. This article concentrates on experiences on a large modern plate mill where the first reference application of this new OGC technology has been installed and is in operation since early 1996.