Building vibration measurement with double magnetic suspension vibrators based on wavelet analysis

In order to measure the vibration of the building generated by large infrastructure equipments, magnetic levitation technique was used. A vibration measurement model with double magnetic suspension vibrators was designed. The function of magnetic repulsion and displacement of the vibrator was obtained by means of the measured and least squares function fitting method. The vibration equations of the two magnetic suspension vibrators were deduced respectively. A simulation model of vibration measurement system with double magnetic suspension vibrators was established. The simulation shows that the sensitivity of the double magnetic suspension vibrators is higher than that of the single magnetic suspension vibrator. When these large infrastructure equipment work, the vibrations of the building were measured. The data components of the vibration signals were analyzed by wavelet decomposition method. Finally, the free vibration waveform of the buildings, the vibration waveform of the building generated by excavators and forklifts were reconstructed. The experimental results show that the magnetic levitation measurement method is suitable for low frequency vibration measurement and its measurement sensitivity is higher. The method can be used to assess the level of vibration generated by large infrastructure equipments.