Open Loop Adaptive Feedback Control of Deposited Zinc in Hot-Dip Galvanizing

Abstract The paper describes the design and implementation of a digital regulation of the deposited zinc on the hot-dip galvanizing line of SOLLAC Florange (St. AGATHE), France.The main difficulties for implementing a high performance feedback control come from the presence of a large and variable time delay (depending on the steel strip speed) and from the nonlinear character of the plant model.The regulation scheme is implemented on a PC connected to the process through an industrial network. It uses a R-S-T digital controller designed on the basis of an identified model.The scheme is open loop adaptative in the sense that the sampling frequency is related to the steel strip speed and that the parameters of the controllers for various regions of operation are stored on a table.The results obtained on the site conclude the paper.