Multi-Point Small Displacement Detection of Bridge using FMCW Radar

Abstract

Structural Health Monitoring (SHM) is a method to monitor the condition of building structures that is useful for detecting damage as early as possible, which is also usually done on bridges. The SHM method using a non-contact sensor is proposed in this study. SHM is done by detecting small displacements using the Radar system. The type of FMCW Radar proposed in the study. FMCW radar is a type of radar that emits a continuous transmission signal that can be implemented on SHM on the bridges, because it can reduce spectrum usage so it is easy to implement. In this paper, a simulation study is conducted in developing a small displacement detection method on the bridge structure with multi-point detection feature using FMCW Radar. The phase data extraction technique was proposed to estimate the small displacement of several points over the bridge. The results show that the proposed method can detect multi-point displacement and provide the estimation of small displacement profile of the bridge. In addition, the study on noise effect on the detection performance has also been performed. The average error value is <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$3.8\times 10^{-4}$</tex> . The noise has less significant effect on the detection performed.