Automatic dimension inspection of industrial parts based on 3D point cloud

An automatic parts dimension inspection method based on scanned point cloud is proposed in this paper. Firstly, the point cloud and the CAD model are registered in the CAD model coordinate system by using Fast Global Registration algorithm. Then, by developing the dedicated inspection program based on the 3D modeling software, the dimensions of the CAD model and the features associated with these dimensions are retrieved, which includes edges, planes, cylinders, spheres, etc., and the dimensions also include the information such as the dimension type, the dimension symbol, the references of the dimension. And then, under the guidance of the dimension information extracted from the CAD model, the corresponding features in the point cloud can be extracted by using Random Sample Consensus algorithm. Finally, the dimensions associated with the extracted features can be calculated by fitting the point cloud features into geometric elements and then calculating the corresponding distance. The whole inspection procedure can be accomplished without human interaction. The feasibility and the accuracy of the proposed method is verified by carrying out the experiment of measuring the industrial parts.