Study on deformation measurement method based on structured light point clouds

Abstract

For the requirement of structural deformation measurement, a deformation measurement method based on structured light point clouds is proposed. A structured light measurement system is built, and the calibration process based on the assumption of the projector's reverse camera and with the help of the checkerboard calibration board is completed. The pattern projected by the projector is designed by using a four-step phase-shift technique assisted by Gray code. By combining with system parameters which have been calibrated, the three-dimensional reconstruction of the object surface is completed. A structural deformation measurement method based on the statistical analysis of the distance between point clouds is proposed, and the principles of three points cloud distance calculation methods including point-to-point, point-to-surface and surface-to-surface are analyzed. The feasibility and accuracy of the deformation measurement method based on the structured light point cloud proposed in this paper are verified via experiments. Experimental results show that this method can achieve out-plane high-precision displacement measurement of structures.