Research on coaxiality error measurement methodology for rectangular spline shafts using 3D point cloud technology.

Abstract For the rapid detection of coaxiality error in rectangular spline shafts, a visual measurement method based on 3D point clouds is proposed. According to the 3D point cloud data of the measured part obtained by a laser scanner, a rotation-guided optimal slicing acquisition method is proposed to obtain the optimal point cloud slice of the journal. The point cloud data points of the major and minor diameters are separated by a distance threshold method. The RLTS-BCT fitting method proposed in this paper is used to fit the slice centers of the major and minor diameters, and the least square method is used to fit the center corresponding to the minor diameter to obtain the public reference axis, finally realizing the measurement of coaxiality error. The experimental results show that the proposed slicing acquisition method has higher perpendicularity. The maximum error of the circle fitting method compared with the results of the Coordinate Measuring Machine (CMM) does not exceed 0.0045 mm, and the maximum absolute error of the coaxiality detection results compared with the CMM results is 4.9 μm, which can meet the requirements of rapid detection of coaxiality error in rectangular spline shafts.