Research On Calibration And Reconstruction Method Of 3D Measurement System Of Surface Structured Light

With the development of industry and technology,the application of 3D measurement technology in aviation,medical,entertainment and other fields is increasing and showing excellent development prospects,and 3D measurement technology is developing towards integration and automation.The 3D measurement technology of surface structured light has the advantages of fast speed,non-contact,wide application range,and high measurement flexibility,so it has received great attention from researchers and the business community and other fields.For 3D measurement technology of surface structured light,calibration and reconstruction methods are the research focus of this technology.The important indicators of this technology are accuracy and speed.This paper focus on the construction of the 3D measurement system model of surface structured light,the calibration of the measurement system based on the phase method,the calibration of the measurement system based on the De Brujin coding method,and the research on the 3D reconstruction method.It establishes a theoretical and technical foundation for the development of 3D measurement technology of surface structured light.The main contents of this paper and the results obtained are as follows:1)The overall scheme of the 3D measurement system of surface structured light is designed,and the components and working principle of the measurement system are introduced.The mathematical imaging geometric models of cameras and projectors in the 3D measurement system of surface structured light are analyzed,and the plane calibration method of Zhang Zhengyou is deduced.Finally,the device selection and software support of the 3D measurement system are introduced.2)The calibration of the measurement system based on the phase method is studied.An automatic matching algorithm between the center mark point and its three-dimensional coordinates is proposed,and then the camera is calibrated by Zhang Zhengyou’s plane calibration method.The nine-step phase shift phase extraction algorithm and the three-frequency heterodyne phase unwrapping algorithm are used to realize the phase unwrapping;the phase information is used to calibrate the projector;and then the joint calibration of the camera and the projector is completed.The experimental results show that the proposed method can obtain higher calibration accuracy than the traditional method.3)The calibration of measurement system based on De Brujin coding method is studied.A calibration method using a circular array calibration board combined with De Brujin sequence color structured light is proposed;the watershed algorithm is used to achieve the segmentation of orthogonal fringe images;the center position and intersection of the orthogonal fringes are extracted based on the Hilditch algorithm;and the Kmeans clustering algorithm is used to achieve self-adaptation color recognition;the matching of the plane pixel coordinates of the camera and the projector is realized by using the uniqueness of the window;and then the calibration of the measurement system is completed.4)The method of three-dimensional reconstruction was studied.The principle of line and line intersection model in the three-dimensional reconstruction method based on spatial analytical geometry is analyzed,combined with the principle of line intersection and calibration parameters,the algorithm for calculating three-dimensional coordinates is derived,the three-dimensional reconstruction of the object is realized,and the error analysis of the standard ball is carried out,and the average absolute error of the measurement is 0.0543 mm compared with the threecoordinate measuring instrument,and the MAE is 0.0738 mm compared with the Flex Scan3 D commercial three-dimensional measurement software,which is in line with the expected indicators.