Model predictive based incremental sheet forming toolpath optimisation

The shaping and forming of metal sheet is a key manufacturing process. Incremental Sheet Forming (ISF) is a novel sheet metal forming technology where the deformation of the metal sheet occurs locally and progressively. Currently, the geometrical accuracy of the shape made by ISF is low compared to shapes made by a stamping process. We address this issue by adopting a linear forming process model based on spatial impulse responses and applying a predictive control scheme to generate an optimised toolpath. Two optimisation strategies are compared based on non-negative least square(NNLSQ) and robust least square(RLSQ) algorithms, and the results suggest the NNLSQ is a better choice in terms of the final geometrical accuracy using a MPC regime.