OPEN LOOP ADAPTIVE FEEDBACK CONTROL OF DEPOSITED ZINC IN HOT-DIP GALVANIZING

Abstract The paper describes regulation of deposited zinc on the new hot-dip galvanizing line of SOLLAC Florange (France), in presence of large and variable time delay and of 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 digital controller designed on the basis of an identified discrete-time model. The scheme is open-loop adaptive: the sampling frequency is related to the steel strip speed, and the parameters of the controllers for various regions of operation are stored on a table. The results obtained on the site conclude the paper (annual saving over 350 000 USD).