基于靶标的小角度结构缝平面检测算法与应用  

Detection algorithm and application of small angle concrete structure joint plane based on target recognition

作　　者：李斌 丁勇[1] 谢东辉 李登华[3] 孙晨 LI Bin;DING Yong;XIE Donghui;LI Denghua;SUN Chen(School of Science,Nanjing University of Science and Technology,Nanjing 210094,China;Jiaokou Reservoir Branch of Ningbo Raw Water Co.,Ltd.,Ningbo 315000,China;Nanjing Hydraulic Research Institute,Nanjing 210029,China)

机构地区：[1]南京理工大学理学院,江苏南京210094 [2]宁波原水有限公司皎口水库分公司,浙江宁波315000 [3]南京水利科学研究院,江苏南京210029

出　　处：《水利水运工程学报》2023年第6期109-116,共8页Hydro-Science and Engineering

基　　金：浙江省水利厅科技计划项目(RB2035);国家自然科学基金资助项目(51979174);国家自然科学基金联合基金项目(U2040221);。

摘　　要：结构性裂缝变化是衡量混凝土坝安全状态的重要依据之一。针对传统视觉测量方法在小角度倾斜拍摄条件下存在测量精度显著下降的问题,根据结构缝变化等效物理模型设计了一种能够适应小角度拍摄的新型靶标,并提出结构缝二维平面变化检测算法。该方法利用射影几何中的交比不变性和灭点的性质,对靶标同心圆圆心进行透视偏差修正,以获取精确的靶标特征点坐标并推导出结构缝在x、y方向的变化量检测算法。将靶标置于滑台上模拟结构缝的变化,从多个方面对检测算法进行验证。室内验证试验结果表明:在不同拍摄角度,甚至小角度拍摄条件下,该方法在x与y方向的测量误差均小于0.1 mm。现场试验中,x与y方向误差均小于0.25 mm,满足规范要求,具有工程应用价值。Structural crack change is one of the important bases to measure the safety state of concrete dams.In view of the problem that the measurement accuracy of traditional vision measurement methods is significantly reduced under the condition of small angle tilt shooting,based on the equivalent physical model of structural joint change,a new target which can adapt to small angle shooting is designed,and a two-dimensional plane change detection algorithm of structural joint is proposed in this paper.This method uses the cross ratio invariance and the property of vanishing point in projective geometry to correct the perspective deviation of the concentric center of the target,so as to obtain the accurate coordinates of the target feature points,and deduce the change detection algorithm of the structural seam in the x and y directions.In this study,the target is placed on the slide to simulate the changes of structural joints,and the method is tested from many aspects.The indoor verification test results show that the measurement errors of this method in x and y directions are within 0.1 mm under different shooting angles,even small angle shooting conditions.In the field test,the errors in x and y directions are within 0.25 mm,which meets the accuracy requirements of the specification.It can realize the accurate detection of two-dimensional plane changes of structural joints under the condition of small angle shooting,and has engineering application value.

关 键 词：结构缝变化 靶标 小角度测量 射影变换 

分 类 号：TV698.1[水利工程—水利水电工程]