Wavelet-based detection of abrupt changes in natural frequencies of time-variant systems
A new method for detection of abrupt changes in natural frequencies is proposed. The method uses the inputoutput algorithm that utilizes the wavelet-based Frequency Response Function (FRF). The major focus is on ridge extraction and occupation measures applied to the FRF characteristics and the estimation of time instants for the abrupt changes in natural frequencies. The proposed methodology is illustrated using simulated multi-degree-of-freedom data and experimental inputoutput data from of a three-floor building structure. The method captures the dynamics of the analysed simulated and experimental time-variant vibration systems. All abrupt changes of natural frequency are identified correctly.
natural frequency time-variant systems system identification abrupt change detection wavelets