Model-Based Control of Slab Shapes in Hot Rolling Processes

We use the example of hot rolling to develop a comprehensive optimization approach that is based on a mathematical model of the underlying manufacturing process. More precisely, we study an optimal control problem that is designed to minimize cutting scrap while taking industrial specifications and technical limitations into account. It is well known that the associated control-to-observation map is non-differentiable due to changes of state resulting from elasto-viscoplastic material behavior and frictional contact. However, we still want to apply gradient-based methods to solve the optimal control problem and therefore have to compute derivatives of cost functional and constraints. To resolve this issue, we first regularize all non-differentiabilities before computing sensitivity information via direct differentiation. We moreover present solution techniques for the regularized problem and discuss numerical results for real-world examples.