Curved layering and path planning of continuous fiber composites based on multi-direction slicing for robotic additive manufacturing

Abstract

Curved path planning methods based on the surface structural characteristics of target models are key technologies for reducing support structure dependence, improving surface quality, and optimizing structural performance in additive manufacturing. The combined forming method of planar/curved surface paths is an important solution to balance the increased manufacturing time cost due to frequent adjustments of multi-degree-of-freedom printing postures. The present study proposed a curved layering and path planning strategy based on the discrete intersection points of multi-directional slices, achieving the unification of planar slicing and curved slicing in the processing logic of the model. Building on traditional planar contour offset methods, it introduced multiple vertical slices, achieving the dimensional transformation of discrete point information from 2D to 3D. Meanwhile, it utilized the normal information of the model's surface to optimize the spatial positions of the discrete points within each horizontal slice, enhancing the consistency of the layer thickness of the generated curved paths. This strategy was applied to path analysis and accuracy discussions on target models like helmet, and experimental validation was conducted using a continuous fiber multi-axis printing platform based on a six-axis robotic arm. The results showed that the curved slicing paths generated exhibited superior theoretical accuracy of surface contours, effectively suppressing the staircase effect. The surface contour accuracy in the fiber orientation direction reached 99.29 %. Furthermore, considering the structural deformation constraints of continuous fiber filaments during printing, the recommended layer thickness range was 0.20 to 0.24 mm for 0.4 mm size filaments.