Research On 3D Measurement Based On Binocular Structural Light For High-speed Railway Train Body

As a very important large-scale curved surface structure on high-speed railway,the surface quality of high-speed train body directly affects the wind resistance performance of high-speed railway running after putty polishing.It is necessary to evaluate the polishing quality by measuring its surface smoothness.At present,the factory adopts manual testing method,which has very low measuring efficiency and difficult to guarantee the quality of testing.The measurement method based on surface structured light has become a research hotspot of large-scale workpiece measurement because of its high accuracy and high speed.Therefore,this paper studies the method based on binocular structured light for three-dimensional measurement of high-speed trian body,aiming at improving the speed and accuracy of overall measurement.The main work and innovation are as follows:1.Three phase unwrapping algorithms based on PSP in structured light coding and decoding are implemented.The advantages and disadvantages of these three methods are analyzed,and the corresponding precision measurement experiments of the two methods are carried out.The phase unwrapping method with the best comprehensive performance in terms of stability and accuracy is obtained.2.In the aspect of phase-based stereo matching,A fast matching method based on "Epipolar Slope-Phase Search Container" is proposed.This method uses coarse-to-fine matching mode,Firstly,pixel-level matching points are obtained by rough matching,and then sub-pixel-level matching points are obtained by interpolation within the neighborhood of rough matching points.This method has the characteristics of fast matching speed and high matching accuracy.3.For the difficulty of two point clouds registration with low overlap area,a rough point cloud registration method based on multi-sphere feature is proposed.It places three standard spheres with different radius in front of the measured object,and calculates the rough registration matrix based on the sphere feature of the standard sphere.Experiments show that the method can jointly two point clouds with low overlap area.The problem of point cloud registration is solved effectively.