铁道科学与工程学报2024，Vol.21Issue(6)：2453-2464,12.DOI:10.19713/j.cnki.43-1423/u.T20231383
基于数字图像相关法的轮轨力测量研究
Research on wheel-rail force measurement based on digital image correlation method
摘要
Abstract
Aiming to address the shortcomings of the strain gauge type wheel-rail force measurement method,this paper studied a non-contact wheel-rail force measurement method based on the digital image correlation method.The position of the non-contact measurement points on the rail surface was determined through force analysis and finite element calculations.Considering the trackside measurement,the overall scheme of the measurement system was designed,and its measurement principle was analyzed.The camera was carefully selected to capture high-quality deformation speckle images of the rail surface measurement area under the action of wheel-rail force.Based on digital image correlation method,the collected deformation speckle images were analyzed,including using a first-order shape function to describe the deformation of the steel rail,and using the zero-mean normalized sum of squared differences function as an index of its shape similarity.Moreover,to improve the measurement resolution accuracy of the system,on the basis of the whole-pixel matching algorithm,sub-pixel level displacement was further obtained by iterating the initial displacement value,and the corresponding strain field was obtained by fitting the displacement field using the least squares method.A wheel-rail force measurement test system with the capability of moving loading was designed and built in the laboratory.Static calibration tests accurately established a linear calibration curve reflecting the mathematical relationship between rail strain and wheel-rail vertical force.Additionally,the influence of factors such as the camera working distance and light intensity on the wheel-rail force measurement was analyzed and discussed.Dynamic measurement tests of wheel-rail force were also conducted under moving loading conditions.Compared with the measurement results of the contact strain gauge method,the maximum error of the non-contact digital image correlation method at the mid-span position does not exceed 0.3%.The results of static and dynamic measurement experiments indicate that the digital image correlation method can achieve accurate measurement of wheel-rail force and is an effective non-contact wheel-rail force measurement method.关键词
轮轨力/数字图像相关法/散斑图像/亚像素匹配/试验研究Key words
wheel-rail force/digital image correlation method/speckle images/sub-pixel matching/experimental study分类
交通工程引用本文复制引用
钟昊,王雪梅,倪文波,魏丞耀,丁军君..基于数字图像相关法的轮轨力测量研究[J].铁道科学与工程学报,2024,21(6):2453-2464,12.基金项目
四川省国际科技创新合作项目(2022YFH0038) （2022YFH0038）
