Structured Light Based Object Panorama Stitching And Measurement System

Shape and size are most basic parameters for human beings to perceive the world,how to get the 3D contour data quickly and accurately has always been a hot and difficult issue of current research.As an active 3D measurement technology,fringe projection is widely used in industrial detection,biomedical and engineering manufacturing and other scientific research and engineering practice fields because of its advantage of high efficiency,speed and noncontact.However,with the continuous upgrading and development of various fields,the traditional single-view 3D information measurement can no longer meet the growing application requirements,therefore,how to obtain the complete outline of the object on the basis of the traditional single-view measurement is very important for the application of expanding fringe projection.In order to solve these problems,we develope and design a system based on structured light to achieve 3D stitching and measurement of objects realizing fast and high-precision measurement of the complete shape of objects.Aiming at the problem that it is hard to obtain the complete 3D contour of the object with high precision,this paper puts forward the following three innovation points:(1)On the basis of fringe projection profilometry,depth constraint and closest phase consistency check are used to improve the accuracy of matching point pairs.(2)For the gamma distortion brought by the projection system,the algorithm of deep learning network based on CNN is proposed for phase prediction,and it is proved that the accuracy can be improved by more than 3 times compared with direct measurement and some traditional methods.(3)For the problem of not being able to obtain the complete 3D information of the object,it is proposed to use the algorithm based on spatial turntable calibration to complete the automatic stitching of the shape contour;for the places that cannot be captured within the camera's viewpoint,a manual stitching algorithm is proposed to capture the vacant part separately and perform the manual supplementary stitching method at the software level based on QT+VTK to realize the complete 3D measurement of the object.Based on all the above work,we designed and produced a 3D scanning system to achieve a single-view scanning accuracy of 0.048 mm and an overall measurement stitching accuracy of 0.17 mm for objects with a view range of 250×200,and we can get the complete 3D data of the object within 3 minutes.