Reduction of shape defects and yield losses by advanced online adaptation of control systems and new operating strategies in heavy plate rolling mills (SHAPEHPM) : final report

The aim of the project was the reduction of shape defects and yield losses in heavy plate rolling by providing new operating strategies, ski-end control and optimised set-up adaptation for ski and control for camber/thickness profile. This approach encompasses the application of the new topometrical measurement system TopPlan® to collect data on plan view shape and ski, advanced FE modelling and rules to predict shape defects and the development and use of advanced online models for ski control. To compensate for the deficits of conventional models and control methods, iterative learning control was developed for a pass-to-pass set-up adaptation of ski control and of camber control that takes into account the cross-thickness profile. The concept has been optimised by runs of a real time HPM simulator built up by online models to predict shape and ski. The developments have been based on the following. • Comprehensive data acquisition campaigns under typical operational conditions on a plate mill inclusive of online flatness measurements. • Pilot mill trials to investigate the influence of the shape factor on the ski-end formation applying a transportable ski-measurement system based on image processing. • Advanced finite element (FE) models of plate rolling roughing stand. • A simplified empirical model describing incremental plan view shape (PVS) evolution on a pass-by-pass basis and application at plate mills. • A ski-form model based on gram decomposition and its application for ski control.