A Novel Laser and Video-Based Displacement Transducer to Monitor Bridge Deflections

Sensors

Jesus Minguez¹  Miguel A. Vicente¹  Dorys C. Gonzalez¹  Thomas Schumacher² 

[1] Department of Civil Engineering, University of Burgos, c/Villadiego, s/n. 09001 Burgos, Spain;Department of Civil and Environmental Engineering, Portland State University, 1930 SW 4th Ave, Portland, OR 97201, USA;

关键词: displacement sensor;    laser beam;    digital video camera;    static deflection;    long-term monitoring;    bridge;   

DOI  :  10.3390/s18040970

来源: DOAJ

【 摘 要 】

The measurement of static vertical deflections on bridges continues to be a first-level technological challenge. These data are of great interest, especially for the case of long-term bridge monitoring; in fact, they are perhaps more valuable than any other measurable parameter. This is because material degradation processes and changes of the mechanical properties of the structure due to aging (for example creep and shrinkage in concrete bridges) have a direct impact on the exhibited static vertical deflections. This paper introduces and evaluates an approach to monitor displacements and rotations of structures using a novel laser and video-based displacement transducer (LVBDT). The proposed system combines the use of laser beams, LED lights, and a digital video camera, and was especially designed to capture static and slow-varying displacements. Contrary to other video-based approaches, the camera is located on the bridge, hence allowing to capture displacements at one location. Subsequently, the sensing approach and the procedure to estimate displacements and the rotations are described. Additionally, laboratory and in-service field testing carried out to validate the system are presented and discussed. The results demonstrate that the proposed sensing approach is robust, accurate, and reliable, and also inexpensive, which are essential for field implementation.

【 授权许可】

Unknown