Hole feature reconstruction of thin-walled sheet metal parts based on T-scan measurement

Due to the low efficiency of the thin-walled hole measurements and the shortcomings relating to the position of the hole and the radius measurement, a method based on T-scan measurements was proposed to reconstruct the characteristics of the hole of thin-walled sheet metal parts. Firstly, point cloud data of a thin-walled hole were obtained with a T-scan, then were sorted into scan line data in accordance with the Euler distance of the successive points in the point cloud data. The points of the plane and the edge points of the thin-walled hole were subsequently gained by processing the scan line point cloud data with an algorithm. Finally, the plane parameters were obtained by applying the robust eigenvalue plane fitting method, which managed the points of the plane, and the hole center coordinates and pore sizes were obtained with the use of the least square circle fitting space. Ultimately, the features of the thin-walled hole were reconstructed. Through measuring and processing test pieces and thin-walled sheet metal parts, this experiment demonstrates that the algorithm can be well applied in practice and that the accuracy meets the requirements of the actual measurement accuracy of sheet metal parts.