Research On 3D Reconstruction System Based On Fringe Projection Structured Light

With the progress and development of social science and technology,the demand for obtaining the three-dimensional shape of objects is more and more extensive.The fringe projection Structured light Iterative reconstruction technology is widely used because of its fast speed and high accuracy.Based on the fringe projection Structured light Iterative reconstruction technology,drawing on the design ideas and structures of existing products,this paper studies the reconstruction principle of the system,and designs a set of highprecision 3D digital reconstruction system.In the process of designing and implementing the Iterative reconstruction system,the following contents are mainly studied:(1)To achieve high-speed and high-precision reconstruction of a stripe projection structured light 3D reconstruction system,four key technologies need to be studied: phase recovery,phase unwrapping,phase error compensation,and structured light system calibration,laying a theoretical foundation for subsequent 3D reconstruction system design.The phase recovery technology focuses on the phase shift method used in this article,and elaborates in detail on how to generate phase shift fringes,recover the phase of the measured object from the phase shift fringes,and prepare data for subsequent phase unpacking and system calibration;Introduce the sources of phase errors and introduce their mathematical models.Introduce two compensation methods for phase errors,which can be flexibly selected to improve system accuracy;Provide a detailed introduction to the calibration of structured light systems,the mathematical models of cameras and projectors,and introduce two methods for projector calibration to achieve phase to three-dimensional coordinate mapping.(2)A multi frequency heterodyne method based on dual frequency stripe projection is proposed to address the problem of a large number of stripes projected by traditional multi frequency heterodyne methods.Encode two sinusoidal components with different amplitudes,frequencies,and phase shifts into a single stripe to obtain the phases of the two frequencies required by the three frequency heterodyne method.Then,encode the high-frequency stripes into the traditional phase shift algorithm to ensure phase accuracy.Finally,use the three frequency heterodyne method to recover the continuous phase of the high-frequency stripes.This method retains all the advantages of the original multi frequency heterodyne method.Compared with the traditional three frequency heterodyne three step phase shift method and the three frequency heterodyne four step phase shift method,the projected fringes are reduced by one and three,respectively,which to some extent improves the measurement efficiency of the system.The high-frequency fringes are encoded using the traditional phase shift method,ensuring the final measurement accuracy.Simulation and experiments have verified the effectiveness of this method.(3)A fringe projection Structured light Iterative reconstruction system is built.Select the required hardware and write the software required for the entire system.The system was calibrated,the accuracy of the system was evaluated,and point cloud data of gypsum spherical models,automotive brake pads,and circuit boards were obtained,achieving good results.