Development of a strip temperature control system with adaptive generalized predictive control

The strip temperature dynamics of the heating furnace of the continuous galvenizing line (CGL) consists of dead time and time lag against the change of various plant variables. The exact identification of these characteristics is difficult because the dynamics is time-varying depending upon the operational conditions and long-term shifts of plant characteristics. In view of these facts, the author applied the self-tuning generalized predictive control to the strip temperature control of the heating furnace, obtained fine control performance, and established a new strip temperature control for the heating furnace of CGL or CAPL (continuous annealing and processing line). This control has been successfully applied at the No.5CGL of Nagoya Works of Nippon Steel Corporation since June 1990 and the basic principle of the control has been transferred to the No.2CAPL of Nagoya Works and the No.2CAPL of Kimitsu Works