Development Of A Structured Light 3D Reconstruction System For The Surface Of Highly Reflective Workpieces

The structured light 3D reconstruction technology is widely used in advanced manufacturing,automatic assembly,cultural relics protection,medical treatment,transportation and other fields due to its simple,fast,and high-precision characteristics.However,it is still subject to many restrictions in practical applications,such as reconstructed The object must be a diffuse reflection surface,etc.In actual industrial production,many workpieces have high surface reflectivity after precision machining,which causes the reflected light intensity in some areas to exceed the dynamic range of the camera,resulting in loss of image information and affecting the reconstruction effect.Therefore,in view of the problem that the traditional structured light 3D reconstruction method cannot completely reconstruct the 3D topography of the highly reflective workpiece surface,based on the Gray code structured light,a structured light 3D reconstruction method with multiple exposures of the camera is proposed to effectively solve the problem of high reflection Three-dimensional reconstruction of the surface of the workpiece.This paper compares the advantages and disadvantages of various high-reflective workpiece surface 3D reconstruction methods,and proposes a camera multiple exposure reconstruction algorithm.According to the calibrated camera response function,the relationship between the pixel gray value and the camera exposure is obtained and its illumination range is obtained.By dividing and calculating the contrast value,multiple exposure times are obtained,and a high dynamic range image is synthesized to solve the effect of high light reflection;for the current structured light system calibration operation is complicated and the error is large,a new method based on local homography is proposed.The structured light system calibration algorithm uses the projector as a reverse camera,uses the camera to take a picture of the calibration board and extracts the corresponding feature points,and then projects the coded fringe sequence to it through the projector and decodes it to realize the feature points in the projector image Reverse positioning on the plane,and then convert the system calibration to binocular stereo vision system calibration;designed a positive and negative Gray code coded stripe pattern,projecting pure white and pure black patterns on the surface of the workpiece to be tested to eliminate the surface of the workpiece The invalid area reduces the calculation amount of decoding.Projecting a set of stripe patterns with opposite positions of black and white stripes can effectively improve the accuracy of decoding and reduce the impact of highlight reflection.The coding pattern is applied to the calibration and3 D reconstruction of structured light system at the same time,which can reduce the complexity of the system.Based on the above research,an experimental platform is built and the proposed algorithm is implemented.A structured light 3D reconstruction system software for the surface of highly reflective workpieces is written.Verify the effectiveness of the method proposed in this article.