融合加速度的桥梁位移响应倾斜摄影监测方法

A bridge displacement monitoring method by fusing acceleration and tilt photogrammetry-based measurement

桥梁的位移响应是结构健康监测和安全状态评估的基础数据。为充分发挥计算机视觉测量结构位移的优势,并提高实测位移的精度,本文提出了一种利用加速度与倾斜拍摄的视觉位移进行数据融合的高精度结构位移监测方法。一方面,通过加速度重构结构动位移,补充结构高频位移分量;另一方面,通过同频带加速度重构位移与视觉位移计算比例因子,减小像素坐标向真实坐标转换的误差。通过室内悬索桥模型实验和室外简支梁现场试验探索了本文方法的有效性。在室内实验中,与线性可变差动变压器位移计测量结果相比,本文方法的归一化均方根误差最大为2.70%,比传统视觉测量方法降低约60%。所提出方法可推进计算机视觉在桥梁健康监测领域的进一步应用。

Structural displacement response is the basic data for structural health monitoring(SHM)and safety condition evaluation.To make full use of the advantages of vision-based sensors,overcome its shortcomings,and improve the accuracy of structural displacement,an accurate structural displacement monitoring method by fusing tilt photogrammetry-based and accelerometer measurement is proposed in this article.On the one hand,the dynamic displacement at higher frequencies is reconstructed by the measured acceleration.On the other hand,the acceleration reconstructed and vision-based displacements in the same frequency band can be used to calculate the time-domain variable scaling factor,which can reduce the error caused by the conversion from pixel displacement to real displacement.Experimental tests on a self-anchored suspension model bridge and field tests on a simply supported beam bridge are carried out to explore the efficiency of the proposed method.The results of experimental tests show that,compared with the linear variable displacement transducer results,the maximum normalized root mean square error of the proposed method is 2.70%which is about 60%lower than the traditional vision-based approaches.The proposed method can promote the further application of computer vision in the field of bridge structural health monitoring.