Event-based modeling and control for the burnthrough point in sintering processes

This paper treats modeling and control for the burnthrough point in industrial sintering processes. First, a simple state-space model for event-time dynamics is derived for a complicated system by introducing events into a continuous variable system. For the control of the sintering process, a two-stage control policy is used. First, optimal interevent time is obtained from an output-constrained receding horizon control with a least-square prediction algorithm. Then the average strand speeds for the interevent times are obtained and applied as a command signal to a motor control system. It is proved that the proposed output-constrained receding horizon control law with a short horizon stabilizes the closed-loop system and the steady-state error for a set-point becomes zero. The real-time experiments are carried out in a POSCO (Pohang Steel Company, Korea) sintering plant and satisfactory results are presented in this paper. Also, computer simulations are carried out and compared with the real-time experiments