Optimized trajectory tracking control of multistage dynamic metal-cooling processes

Tracking a trajectory of multistage dynamic processes optimally is a challenging problem and spans a wide spectrum of interesting applications. Run-out table (ROT) cooling of hot strip is a supreme example of a thermal multistage process and entails special control considerations. In this paper, we formulate an optimized trajectory-tracking controller, to track the temperature throughout the multistage cooling process. It is based on optimal solutions with respect to a defined performance objective, subject to specified dynamic constraints. ROT cooling is chosen as the benchmark application for qualitative and quantitative evaluation of the proposed control structure. Optimization and optimal control play a central role in obtaining meaningful and tractable problem formulations and determining the necessary and sufficient conditions, which lead to optimal and efficient solutions.