Constrained model predictive control of an incremental sheet forming process

Model Predictive Control (MPC) has been applied in a range of industrial applications, and part of its popularity is that it can cope with a constrained system, providing an optimal control for a certain performance index. Incremental Sheet Forming (ISF) is an emerging progressive sheet metal forming technology where the deformation occurs locally. It is best suited to customised and one-off or short-run production, because ISF does not require costly individual tools, dies or punches to be manufactured. The geometrical accuracy of the shape made by ISF, is however, lower than the conventional processes, such as stamping. We address this issue by using a constrained model predictive control scheme to optimise the tool trajectory of this process. A simplified linear forming process model is first derived, which is modified then to handle the “tool contact” issue and after that a full MPC formulation is established. Two types of shapes are produced on an experimental rig, and the experimental results show that the final geometrical errors can be reduced compared to a standard contour following approach.