Research On Key Technology Of Structured Light Three-dimensional Reconstruction Based On The Combination Of Monocular And Binocular

With the rapid development of industrial modernization in China,manual contact product detection in traditional industrial production can no longer meet the production demand.Optical 3D surface profilometry measurement,with advantages such as non-contact,high precision and fast speed,has been widely applied in industrial measurement,medical orthopaedics,equipment manufacturing,reverse engineering,cultural relics protection and other industries.Among them,fringe projection profilometry is the most commonly used optical three-dimensional measurement method,which has the characteristics of high precision,low cost and simple device.However,the structured light 3D shape measurement technology based on this still faces challenges such as phase error,robustness,speed,and accuracy.This paper mainly studies the key technologies of structured light 3D reconstruction combined with monocular and binocular,focusing on structured light encoding and decoding that affects shape measurement,phase unwrapping error correction,calibration of structured light system with monocular and binocular combination,and point cloud fusion for the combined structured light system.The main research contents of this paper are as follows:(1)Encoding and decoding method of structured light.The gray code,phase coding and other phase unwrapping methods are analyzed and compared.Aiming at the lack of code words of the traditional phase coding method,as well as the problems of insufficient robustness and high algorithm complexity of the current improved phase coding method,a composite cyclic is proposed.By comparing the experimental results of relevant phase coding methods,the proposed method has stronger robustness and lower algorithmic complexity.(2)Phase unwrapping error correction.The formation of phase unwrapping error is analyzed,and the correction method of this error is discussed,which is further summarized into error correction based on space domain and error correction based on time domain.The effect analysis of phase unwrapping error correction was carried out using methods such as median filtering and complementary gray coding.It was found that median filtering still has significant errors,and complementary gray coding requires additional introduction of patterns.A displaced complementary phase unwrapping error correction algorithm is proposed.This method recombines the fringe orders in a displaced complementary manner to achieve efficient phase unwrapping error correction.Relevant experiments have demonstrated its effectiveness.(3)Unified calibration of monocular and binocular combined with structured light.The selection of the calibration board,the experimental operation during calibration,and the location extraction of the marker points are discussed.At the same time,the calibration relationship between the camera and the projector,and the accuracy error are analyzed and compared experimentally.Unify the structured light calibration of the combination of monocular and binocular,and analyze the importance of calibration and perspective unification for point cloud registration,and effectively complete the rigid body transformation of point cloud under three perspectives.(4)Point cloud fusion of monocular and binocular combined with structured light system.For the problem of insufficient reconstruction accuracy of monocular structured light,a higher-precision binocular structured light system is used to make up for it.At the same time,areas where the binocular structured light system fails to reconstruct due to factors such as reflections and occlusions are compensated by left and right monocular structured light systems.The experimental results prove the high precision and strong robustness of the point cloud fusion system.