Data mining and state monitoring in hot rolling

An overview of state monitoring in hot rolling is reviewed, and a new concept of state monitoring is shown. Based on a detailed analysis of all factors a state monitor is proposed. A system state corresponds to the proper product quality. If the system is leaving the area of required quality in the state space, a signal is given with the evaluation of situation. Self-organising maps (SOM) are especially suitable in analysing the very complex process of hot rolling. Application of SOM helps to discover hidden dependencies influencing the quality parameters, such as flatness, profile, thickness and width deviation as well as wedge and surface quality. Results from the analysis of more than 70 parameters in 16,000 strips gave the state space used in state monitoring based on online data sampling. The coloured visualisation map shows the state space enabling prediction of product quality.