Application of modern control and modeling techniques to extrusion processes

Extrusion uses compression to deform a material through a die, creating an arbitrary shape. This process is qualitative, nonstationary, and nonlinear. The operator indirectly controls the process by set-point or direct adjustment of ram speed. Thus, industrial extrusion process control is a rich problem domain for control system engineers. We describe our work on aluminum extrusion. Our problem decomposition is presented. The conventional process control practices and analyses, primarily static, are reviewed. A process model with local material response is required for control. An extension of Kiuchi´s model (1986), based on upper bound analysis, is developed. Numerical and experimental simulation results are presented. Two control problems are formulated and developed based on this local perspective