It is often difficult to obtain the high-precision inner cavity contour size and 3D model of parts and components in reverse engineering. This paper proposes a method that uses a sequence of section images of a part to reconstruct their 3D models. This method cuts the part layer by layer to obtain the sectional images and extracts the 3D information of the sectional image contours to generate point clouds. These point clouds are then used to reconstruct a 3D model of the part. High contrast material is used to embed the target part for pre-processing. A machining centre was used to mill the part layer by layer vertically to acquire high precision section profile images. The improved Canny edge detection operator was combined with the spatial moment sub-pixel subdivision algorithm to improve the edge detection accuracy. The camera imaging model algorithm transforms the coordinates of the image edge position to obtain a high-precision 3D point cloud of the part. The 3D solid model of the target part was obtained using NURBS surface reconstruction. The results show that the 3D model reconstruction method using the profile sequence of the cross-sectional images is independent of the complexity of the part’s structure and the complete internal structure of the part can be obtained. The proposed edge detection algorithm significantly refines the edge position of the contours in the cross-sectional image and the measurement accuracy was improved. This method improves the minimum deviation to 50 μm. The shape accuracy of roundness, cylindricity and perpendicularity of the structure is high. The proposed method can meet the reverse precision requirements in general precision machining.

逆向工程往往难以获得高精度的内腔轮廓尺寸和零部件的3D模型。本文提出了一种方法，该方法使用零件的一系列截面图像来重建其 3D 模型。该方法将局部逐层切割得到截面图像，并提取截面图像轮廓的3D信息生成点云。然后使用这些点云来重建零件的 3D 模型。高对比度材料用于嵌入目标部件进行预处理。使用加工中心垂直逐层铣削零件，以获取高精度截面轮廓图像。改进的Canny边缘检测算子结合空间矩亚像素细分算法提高边缘检测精度。相机成像模型算法对图像边缘位置坐标进行变换，得到零件的高精度3D点云。使用 NURBS 表面重建获得目标零件的 3D 实体模型。结果表明，利用截面图像轮廓序列的3D模型重建方法与零件结构的复杂程度无关，可以获得零件的完整内部结构。提出的边缘检测算法显着细化了截面图像中轮廓的边缘位置，提高了测量精度。这种方法将最小偏差提高到 50 μm。结构的圆度、圆柱度和垂直度的形状精度高。