A new Model and Control of Coating Process at Galvanizing line

This paper proposes a new practical synthesis model for coating weight control and robust design method of feedback controller in galvanizing process. The model combines both long term and short term model. Long term model have a function of classification, averaging and learning based on real measured data. Short term model is differential model based on linear change of inputs and outputs. A set of practical controller and a robust design method of feedback controller is proposed so that it can attenuate quickly the errors caused by time-delay and modelling error. The proposed model with controller were applied to continuous galvanizing line(CGL) at Kwang Yang Steel Works. As the results, a good performance on the deviation control of coating weight was obtained at top of coil and also the uniform coating weight on the surface of strip was realized.