Sarwar Muhammad Zohaib, Park Jong-Woong
Department of Structural Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.
School of Civil and Environmental Engineering, Chung-Ang University, Dongjak, Seoul 06974, Korea.
Sensors (Basel). 2020 Feb 18;20(4):1109. doi: 10.3390/s20041109.
Structural displacement is an important metric for assessing structural conditions because it has a direct relationship with the structural stiffness. Many bridge displacement measurement techniques have been developed, but most methods require fixed reference points in the vicinity of the target structure that limits the field implementations. A promising alternative is to use reference-free measurement techniques that indirectly estimate the displacement by using measurements such as acceleration and strain. This paper proposes novel reference-free bridge displacement estimation by the fusion of single acceleration with pseudo-static displacement derived from co-located strain measurements. First, we propose a conversion of the strain at the center of a beam into displacement based on the geometric relationship between strain and deflection curves with reference-free calibration. Second, an adaptive Kalman filter is proposed to fuse the displacement generated by strain with acceleration by recursively estimating the noise covariance of displacement from strain measurements which is vulnerable to measurement condition. Both numerical and experimental validations are presented to demonstrate the efficiency and robustness of the proposed approach.
结构位移是评估结构状况的一个重要指标，因为它与结构刚度有直接关系。已经开发了许多桥梁位移测量技术，但大多数方法需要在目标结构附近设置固定参考点，这限制了现场应用。一种有前途的替代方法是使用无参考测量技术，该技术通过使用加速度和应变等测量值间接估计位移。本文提出了一种通过融合单加速度与从共置应变测量中导出的拟静态位移来进行无参考桥梁位移估计的新方法。首先，我们基于应变与挠度曲线之间的几何关系，在无参考校准的情况下，提出将梁中心的应变转换为位移。其次，提出了一种自适应卡尔曼滤波器，通过递归估计易受测量条件影响的应变测量位移的噪声协方差，将应变产生的位移与加速度进行融合。同时给出了数值和实验验证，以证明所提方法的有效性和鲁棒性。
