Research On The Binocular Structured Light 3D Imaging System

In recent years,the traditional measurement methods are gradually replaced by machine vision technology and widely used in industrial testing,reverse engineering,virtual reality,medical diagnosis and other fields currently.Three dimensional measurement technology is one of the important branches of its field,And structural light and binocular vision are the most widely used methods in three dimensional measurement.The binocular vision principle is relatively simple,but it is difficult to obtain the depth information which corresponding to the texture less or repeated region,and the matching calculation cost is generally large.The structural light system can increase the surface texture and has high reconstruction accuracy,but the calibration and non-linear error correction process of the projector are complicated.In view of the above two kinds of measurement technology characteristics,this topic presents a binocular structured light 3D imaging system combining binocular vision and structured light.In this system,the structural light is only used to increase the surface texture of the object,matching the corresponding point is still based on binocular system principle,thus the projection equipment calibration is avoided.And reduce the excessive search range caused by the camera's high resolution with the introduction of disparity gradient and the initial disparity,while ensuring accuracy,effectively improve the matching speed.The scheme not only guarantees the accuracy of this system,but also improves the matching speed effectively.This paper mainly includes the following aspects:1.In order to solve mismatching caused by the surface of the object is textureless,this paper combines binocular system which principle is simple and the structure light which can increases surface texture of the measured object,proposes a binocular structured light three dimensional imaging system.Discusses the similarities and differences between the binocular structure light system and the traditional binocular vision,analyzes the binocular vision principle and selects the structural light scheme used in this subject.2.Clarifies the essence of binocular structured light scheme.Completes the monocular calibration and the accuracy and its influencing factors are analyzed based on the analysis of the camera imaging mathematical model and the principle of the plane calibration method.The calibration between two cameras in binocular structure light scheme is realized.The binocular structure of the optical system is corrected so that the matching of the corresponding points will be from two dimensions to one.3.In order to solve the problem of mismatching of traditional binocular matching algorithm in textureless object,this paper introduces the structured light and proposes a fast and high-precision dense quadratic matching scheme based on the introduction of the initial disparity and the disparity gradient which can reduces the search range.Experiments show that the proposed scheme not only solves the problem of mismatching caused by textureless,but also reduces the reconstruction time compared with matching directly after project the structured light.4.Build the hardware platform of this system and determine system measurement parameters.Analyzes the system software flow and develops the system software modules such as system calibration,image acquisition and 3D reconstruction.Selects calibration plate as the standard object to test the accuracy of this system.