Equal-Arc-Length filling and efficient partitioning strategy for laser surface texturing on complex curved surfaces

In laser surface texturing on complex freeform surfaces, curvature variation often distorts the spatial spacing of filling trajectories, leading to non-uniform laser energy deposition and reduced machining consistency. Meanwhile, under high-density discretized path conditions, large-scale point sets involved in surface partitioning further limit engineering efficiency. To address the coupled challenge of machining stability and computational efficiency, this study proposes an integrated method that combines projection-corrected equal-arc-length filling with rapid curved-surface partitioning. First, a projection-correction mechanism is introduced into the equal-arc-length projection framework. Unlike conventional equal-arc-length projection that only regulates single-path arc length, the proposed method simultaneously compensates arc-length distortion and inter-path density variation during two-dimensional pattern mapping, ensuring consistent real spatial spacing of filling trajectories on curved surfaces. Second, a rapid partitioning strategy is developed by combining local two-dimensional grid discretization with surface-normal constraints. By transforming global point-cloud clustering into representative-point partition mapping, the computational complexity is significantly reduced while partition continuity is preserved. Five-axis laser surface texturing experiments on spherical, wavy, and general freeform surfaces demonstrate that the proposed filling strategy achieves machining stability comparable to planar conditions even in high-curvature regions. The groove depth remains stable at approximately 86 μm, whereas the minimum depth obtained by the conventional method is only about 68 μm. The width error of microstructures is controlled within 3%, and the depth error is generally below 6%. In addition, the proposed rapid partitioning method reduces the computation time to only 0.3%–3.5% of that required by the conventional method while maintaining partition consistency. The proposed method provides a practical and efficient solution for stable laser surface texturing on complex curved surfaces.