Research And Designing For3-D Shape Measurement Based On Grating Projection

With the development of measurement techniques, the non-contact three-dimensional morphology based on computer image processing technology and photogram metric measurement techniques have become the main research direction of the measurement technology. Because of the measurement speed, high precision and so on, grating projection measurement techniques is the hot issue of non-contact measurement technology. This paper is the study of grating projection3D measurement technology. The main contents are as follows:First, model of the grating projection measurement techniques, the key technologies of the grating projection measurement techniques, and especially the four-step phase shift method, Gray coding method and the principle of multi-frequency heterodyne and phase unwrapping error correction method were studied in this thesis;Secondly, we built a3D shape measurement system based on grating projection, studied the selecting of the various parameters in the building process and the calibration for system, and we used the built system verifying some of the principles and methods in the grating projection measurement techniques.Thirdly, we studied the splicing method of the multi-angle measurement point clouds, we compared the accuracy of the transformation matrix solved by the Quaternion method and the Singular value decomposition, and did the point clouds splicing experiments. Through our research, we laid the foundation of the panoramic measurements from360degrees.Finally, we did shape experiments by our designing system, analyzed the accuracy and error of the results, and studied the method to improve the measurement accuracy of the system.By this paper, we completed the basic research for measurement technology based on grating projection.we built a three-dimensional shape measurement system, and did the three-dimensional shape measurement experiments. The done Work in this paper can do much help for a more in-depth study of the grating projection measurement technology.