Discreet control of annealing process with utilization of indirect measurement

At technological processes of metallurgy and machine industry is steel annealing one of the most important operations have influence on production in term of the efficiency, quality and costs. By selection of suitable control of annealing process of the steel coils is possible to increase quality of annealed batch and economic efficiency of the furnace operation. In this paper is described control of annealing process of the steel coils by using of discreet feed-back controller PI and PID based on behaviour of inner temperature inside the coil. Indirect measurement system of the inner temperatures indirect measures temperature inside the coil that is not measurable without destruction of the coil. Indirect measured temperature inside the coil in chosen place (coolest place in the coil) is as input to the algorithm of the feed-back control. This control adjusts atmosphere temperature for next control step, based on error calculation between required inner temperature and indirect measured inner temperature. Inscribed control algorithm was verified with utilization of simulation model of the steel coil's annealing process based on indirect measurement system of the inner temperatures.