Operating Modal Analysis of the Turntable on a Working Road-Header Using DTCWT

In order to identify the main vibration modes of the turntable on a working road-header, the Duall-tree Complex Wavelet Transform (DTCWT) is carried out firstly over the acquired vibration data, to achieve frequency division and noise reduction. Operating modal analysis is then carried out using Auto-Regressive and Moving Average model (ARMA). This data processing composed of DTCWT and ARMA is proposed to monitor the state of the turntable in the aspect of vibration modes changing. The processing results based on vibration data from different test points and time periods show that this proposal is feasible for the assembled turntable. Also, according to the identified first 12 intrinsic frequencies, it is suggested to avoid drive signal at frequencies around 311 Hz, 425 Hz and 540 Hz to decrease mechanical noise and abrasion of the turntable.