Adaptive milling for contours on deformed surface based on on-machine measurement and optimized parallel projection

Machining contours on a large thin-walled part is a difficult task due to inevitable deformation of the actual part. The deformation of the contour can significantly influence the rigidity of the thin-walled part; thus, it is of importance to minimize the deformation of the contour compared with the design contour. This paper proposes a novel method to adaptively calculate the optimal contour on the deformed surface based on optimized parallel projection. The geometry data of free-form surface is obtained by on-machine measurement (OMM), and then, the actual surface is reconstructed using the measurement data. The reconstructed surface is matched with the design surface, and then, the design contour was projected onto the reconstructed surface to obtain the locating contour. The iterative nearest point (ICP) algorithm is used to adjust the design contour to match the locating contour. Finally, the projection direction is optimized to minimize contour deformation, and the adjusted contour is projected onto the reconstructed surface along the optimal direction to obtain the new contour. The effectiveness of this method is verified by machining and measuring experiments.