Many dynamic signals of mining machines are transient, such as load signals when roadheader’s cutting head being cut-in or cut-out and response signals produced by these loads.For these transient signals, the traditi...Many dynamic signals of mining machines are transient, such as load signals when roadheader’s cutting head being cut-in or cut-out and response signals produced by these loads.For these transient signals, the traditional Fourier analysis method is quite inadequate.The limitations of analysis, resolution by using Short-Time Fourier Transform (STFT) on them were discussed in this paper. Because of wavelet transform having the characteristics of flexible window and multiresolution analysis, we try to apply it to analyse these transient signal. In order to give a pratical example,using D18 wavelet and Mallat’s tree algorithm with MATLAB, the discrete wavelet transform was calculated for the simulating response signals of a three-degree-of freedom vibration system when it Was under impulse and random excitations. The results of the wavelet transform made clear its effectiveness and superiority in analysing transient signals of mining machines.展开更多
文摘Many dynamic signals of mining machines are transient, such as load signals when roadheader’s cutting head being cut-in or cut-out and response signals produced by these loads.For these transient signals, the traditional Fourier analysis method is quite inadequate.The limitations of analysis, resolution by using Short-Time Fourier Transform (STFT) on them were discussed in this paper. Because of wavelet transform having the characteristics of flexible window and multiresolution analysis, we try to apply it to analyse these transient signal. In order to give a pratical example,using D18 wavelet and Mallat’s tree algorithm with MATLAB, the discrete wavelet transform was calculated for the simulating response signals of a three-degree-of freedom vibration system when it Was under impulse and random excitations. The results of the wavelet transform made clear its effectiveness and superiority in analysing transient signals of mining machines.
