Design And Implementation Of Rail Surface Defects Measurement System Based On Machine Vision

On the modernization process of rail surface defects measurement,it requires depth and area as a quantitative standard,which provide quantitative information as a standard real-time judgment of rail surface defects.In response to these functional and measurement of real-time,accuracy requirements,this paper presents a measurement system for defect detection and measurement,based on machine vision and structured light measurement.The main research content of this paper are as follows:(1)The classification of standard rail cross section features information and research on common rail surface damage classes.Combined with optical model and rail surface defect measurement needs,a rail defect measurement system was designed,which concerned to be vulnerable to optical problems.(2)Study of rail surface defects of optical imaging characteristics and comparison of several methods for image enhancement and noise,Gaussian filter response to rail features noise reduction and contrast limited Adaptive histogram equalization for image enhancement.The gray-level integral projection and gray correlation method to locate the block part of the image,using Canny operator image positioning information on the edge of the image.(3)In structured light measuring system using light intensity distribution close to a Gaussian distribution of proposed a Hessian matrix-based template and use the gray mass estimated by the method of laser stripe,and on location in the center line of the Hessian matrix of the exact location.Using Z Zhang calibration method,developed a compatible procedure with checkerboard calibration and circles calibration.(4)In the measured points cloud,combined with standard rail line and ARC characteristics estimated initial rotation of the point cloud information and presented by trigonometric point in smaller linear estimation methods,improve the efficiency of the iterative closest point.Research the type of rail proposed location of rail surface damage of normal value and area calculation method used to quantify the rail.This article has the following innovations:(1)Improvement of extraction method of laser stripe in high speed and high precision.(2)Preliminary estimated by standard rail point and line features rotating translation matrix and linear approximate solution of nonlinear equations,expedite the computation.(3)The quantitative standards for rail,and can specify rail eliminated through relevant technical standards.Through theoretical study and engineering practice of combining complete rail surface damage measurement system design and targeted research on key issues,solved the technical difficulties of rail defects detected.