Research On High-precision 3D Measurement Technology Based On Polycular Line Structured Light

Under the background of continuous development of science and technology and large demand for automation,3D measurement technology has higher requirements in industrial production,medical technology,automobile manufacturing,reverse engineering and other fields.With computer application as the technical means and image processing technology as the focus,the structured light three-dimensional measurement method develops rapidly,which has the advantages of high precision,fast measurement,and no need to touch the measured object,so it has been widely used in various industries and paid attention to by scholars.Based on the linear structured light3 D measurement technology,this thesis builds a four-eye single-line linear structured light measurement system to obtain the 3D information of objects by laser scanning.Since cameras with different resolutions were adopted,the entire system model was initially studied,and the camera placement was designed.Then,the line structured light technology is studied,including camera calibration,image correction,and light strip extraction.Finally,the fusion of mixed stereo vision with different resolutions is studied to realize the 4-eye system to restore the target three-dimensional information.Firstly,the structure of the four-eye single-line structured light system is introduced.The system adopts 2×2 camera array,of which the laser is located in the center;the camera array and the laser are fixed on the conveyor belt together.In this system,the object to be measured is placed in the field of view of the camera,the camera array and the laser are moved by the conveyor belt,and the laser completely scans the target to obtain its three-dimensional information.Secondly,the influence of parameters or techniques in each step of linear structured light on 3D reconstruction results is summarized.During the whole process of 3D reconstruction,the internal and external parameters of the camera were obtained by camera calibration.According to camera calibration parameters,image distortion correction and polar-line correction are performed to simplify parallax calculation.Different laser light strip extraction algorithms,including extreme value method,gray gravity center method and Steger method,were used to select the optimal algorithm.Finally,in order to realize the fusion of mixed stereo vision with different resolutions,the vision with the same resolution was reconstructed according to the binocular line structured light 3D reconstruction method,and then the results of different resolutions could be matched by image processing.Finally,the final results were obtained by using the existing stereo matching algorithm to realize the 3D measurement task of the multi-view system.The research on the high-precision three-dimensional measurement technology based on polycular structured light in this thesis has obtained good results in the laboratory,and has higher precision than the binocular system,which has a certain guiding role for scenes with higher three-dimensional measurement requirements.