Input design for large-scale sheet and film processes

Manipulated variable moves are computed to maximize the information contained in experimental data collected from sheet and film processes. The experimental design procedure minimizes the confidence ellipsoid of the critical model parameters over the manipulated variables subject to their physical constraints. For a simulated blown film process, the model is 1 order of magnitude more accurate than that identified from the industrial standard bump test experiments. The improved accuracy results in a 37% reduction in closed-loop thickness variations. This indicates that substantial benefits can be achieved by incorporating the optimal experimental design algorithm into industrial sheet and film process control algorithms.