Modal parameters identification of elastic drive systems using the Wavelet Transform

Wavelet theory has become a powerful mathematical tool and an important signal processing means for its distinct utilities and its numerous advantages. This paper presents its usefulness on modal identification of a special class of electromechanical systems: the elastic drive systems. It is shown that the Wavelet Transform (WT) of the impulse response of an elastic drive system allows the estimation of the natural frequencies and damping ratios. The method is based on the ridges and skeletons of the WT. The Shannon entropy has been used to optimize the chosen modified Morlet wavelet. The accuracy of the developed method is confirmed by applying it to an elastic Two Mass-Model (2MM) and Three Mass-Model (3MM) systems. The simulation results obtained check the efficiency of the developed identification method even in presence of noise.