Research On Key Technologies Of 3D Vision Measurement Based On Fringe Projection

Three dimensional measurement vision technology has the advantages of non-contact,fast speed and high accuracy.It has broad application prospects in many fields,such as intelligent manufacturing,industrial robot guidance,reverse engineering,and so on.The 3D measurement technology of coded structured light based on single camera and projector is a kind of measuring technique with low-cost,moderate measurement accuracy,stable and reliable.And it has been paid extensive attention to intelligent manufacturing and precision assembly and other emerging industries.But this method is based on triangulation principle.It may restrict the effective field of view of the system due to the problem of single camera occlusion caused by the steep and complex contour surface or the shadow part.This problem has become an inherent defect of the camera-projector measurement system,which affects the application of the measurement technology.To overcome the well-known inherent problem of the occlusion caused by single-camera-projector system,A three-dimensional measurement method based on camera-projector-camera structured light system is proposed.The system measurement theory and implementation method are detailed.In system modeling,the camera-projection-camera system is considered as two independent camera-projector units.After obtaining two sets of point cloud data in these two independent systems respectively,the high accuracy measurement point cloud data is obtained in the same spatial coordinate system using the introduced system calibration methods and coordinate system unification techniques.In order to further reduce the error of point cloud fusion caused by physical environment,system calibration and other errors,an improved ICP registration algorithm is implemented.The algorithm can better achieve point cloud fusion(fusion accuracy of about 0.02mm),and achieve a higher accuracy global measurement result.(within the working distance 1000 mm,the relative error of repeat measurement is about 0.2%).In this paper,a 3D reconstruction and measurement system which is dual-camera based on fringe projection is built.The feasibility and effectiveness of the scheme are verified by the experimental results.