Research on automatic spraying technology for 3D shoe uppers

Purpose This study aims to address the challenges of boundary detection and path discontinuities in the 3D shoe upper gluing process by proposing a novel method for robotic trajectory planning. Design/methodology/approach The method begins with aligning sole and upper point clouds using non-rigid registration. The overlapping upper region is segmented via the K-nearest neighbor algorithm, and boundary points are extracted. Offset path is calculated based on local geometry to generate the robot’s glue path, ensuring smooth spraying by minimizing pose changes between adjacent points. Findings Experiments conducted on six shoe types demonstrate that the proposed method achieves a boundary recognition accuracy within 2 mm. Real-world glue spraying experiments confirm its effectiveness and practical feasibility for automated processes. Originality/value This study introduces a robust method for recognizing shoe upper boundaries and generating continuous robotic spray paths, addressing key limitations in current approaches and advancing automation in footwear manufacturing.