In situ three-dimensional laser machining system integrating in situ measurement, reconstruction, parameterization, and texture mapping

This paper proposes a novel in situ three-dimensional (3D) laser machining system that combines 3D projection algorithms with in situ measurement and 3D modeling. This system forms a complete “scanning-modeling-projection-machining” integrated processing system for rapid pattern machining on the free-form surfaces. In situ measurement was conducted by self-scanning of the 3D galvanometer scanner. A high-efficiency Delaunay triangulation algorithm was employed for the 3D reconstruction to generate a quality-controlled 3D model. The Least-Squares Conformal Mapping (LSCM) and As-Rigid-As-Possible (ARAP) algorithms were employed for model parameterization. Local parameterization and bitmap vectorization methods were proposed to improve the accuracy and speed of parameterization and texture mapping. In situ machining software was developed, and the algorithms were verified by in situ machining experiments. The LSCM algorithm achieves fast processing speed but suffers from a large distortion if the model is complex. The ARAP algorithm can further ensure the accuracy of the parameterization through iterative calculation. The developed model can better guarantee the model quality for parameterization. The 3D projection algorithm can transfer the two-dimensional (2D) pattern on a 3D surface, and the in situ method eliminates the necessity for assembly and clamping of parts. The local parameterization and bitmap vectorization methods improve both the accuracy and efficiency of 3D projections. Therefore, the proposed in situ machining system has practical application value for the rapid processing of patterns on curved surfaces.