基于自适应多曝光的反光工件三维测量方法OA

To solve the issue of point cloud data loss in reflective workpieces,the three-dimensional measurement method based on adaptive multiple exposures was investigated.The binocular structured light measurement system was designed,and the workpiece point cloud was generated by phase retrieval,phase-based stereo matching and three-dimensional point calculation.The initial sequence of exposure times was determined,and the corresponding initial images were acquired to conduct the statistical analysis of overexposure ratio in the initial images.The relationship between initial exposure time sequence and overexposure ratio was constructed for enabling the adaptive calculation of final exposure time sequence for point cloud generation by the predetermined overexposure ratio.By fusing the multiple exposure images,the point cloud of the reflective workpiece was computed.The system accuracy was evaluated using stepped calibration block,and the experiments on aluminum guide plate and aluminum side plate were conducted.The results show that the average planar distance error of the binocular structured light measurement system is 0.126 9 mm.Compared with the single-exposure imaging method,the proposed approach using fixed overexposure ratio can generate more complete point clouds for different aluminum alloy workpieces with the number of valid points increasing by 55％and 42％for aluminum guide plate and aluminum side plate,respectively.The proposed method effectively enhances the completeness of point clouds for reflective workpieces.