Global Continuous Path-Planning for 3D Concrete Printing Multi-Branched Structure (2023-04)¶

3D concrete printing as a promising construction technology is of high manufacturing freedom for various freeform civil structures. Appropriate path planning is crucial for the implementation, efficiency, and quality control of 3D concrete printing. While the widely adopted path planning methods of zigzag and contour-parallel paths for structures with multiple branches, such as lightweight-truss and wall structures, are liable to defects, sharp turns, and discontinuities. To address this issue, this study proposes an adaptive path-planning method based on medial-axis decomposition and the transfinite mapping method for multi-branched regions. Medial-axis method aided to parameterize and decompose the model by morphology is employed in this work. The printing paths are generated by template-path based transfinite mapping and automatically connected to derive a continuous global-printing path. Considering the practical 3D printing construction, printing path of solid- and grid-filling are detailed in this research and verified by several case studies. The printing results show that: for solid filling, the proposed method can eliminate discontinuity, minimize sharp turns, and avoid defects; for grid filling, the proposed method can support several types of grid generation with desired global continuity.