Identification of the moving vehicle presence on the bridge with the time-frequency analysis

Abstract

The article presents the application of common techniques of signal processing as the Wavelet Transformation and Short-time Fourier Transformation to detect the position of the moving vehicle on the bridge. The measured acceleration in the middle of the span of the investigated bridge structure are used for this purpose. The aim of the analysis is to determine the time when the vehicle comes to the bridge and when it leaves. This can be important to know if there is required to investigate free and forced vibration of the bridge separately. It is done for two cases that differ in presence of the obstacle which is positioned on the road in the middle of the span. The obstacle is used to increase the dynamic excitation of the bridge. It is recommended by Slovak standard STN 73 6209 for measurement of dynamic characteristics of bridges as a source of excitation.