Research On Measurement Method For The 3-D Shape Of Complex Object Surface With Grating Projection

Construction of physical simulation experiment is an effective method of researching the geological structure, and also is an important means to help geologists to understand the process of tectonic deformation and Formation mechanism. The essence of physical simulation is to research the causes of geological structure and evolution, using the principle of similarity, according to the similarity theory of campaign and geometric theory, for the qualitative and quantitative analysis of geological structure. On the basis of the large number of related literature at home and abroad, measurement methods for the three-dimensional shape of complex object surface with grating projection are researched and improved, and a three-dimensional surface shape measurement system is established using a typical structure of cross-axis in this paper. The experiment shows that the system can measure the three-dimensional shape of complex object surface more quickly and accurately. The main contribution of this paper is as follows:1. The hardware in this measurement system of three-dimensional profilometry that consists of projector, CCD camera, image collecting card and computer is designed. At the same time, a software package for measurement system is developed with MATLAB 7.0, and the system has been calibrated.2. Phase-calculating algorithm of the grating image is studied to obtain the main phase of stripes, in order to get the main phase of the surface of objects. An improved quality map (The derivative variance correlation map integrating edge detection information) is proposed based on the study of traditional quality maps. By comparing the traditional quality map and the improved quality map of simulated objects and real complex objects, the experimental results show that the improved quality map can be better to reflect the quality of the data.3. After Studying the principle of phase unwrapping algorithm, an improved quality map (The derivative variance correlation map integrating edge detection information) is proposed based on the study of traditional quality maps, for phase discontinuity arising from the hole and edge steep side, and is used to unwrap the phase of analog objects and real objects. It is proved that this measurement method for three-dimensional shape of object surface with grating projection presented in this dissertation can obtain feasible and effective results.