Based On The Wigner Distribution Of Non-stationary Signal Of The Whole It And Application,

In a long period of time, condition monitoring of the machinery and fault diagnosis are based on the analysis of the signal coming from single channel. The vibration of the rotor is a dimensional conception. The signal coming from single channel only reflects the vibration of the rotor in the sensor orientation, so it can't accurately offer integral information. The Vector-spectrum, one of the full information techniques, can overcome the incompletion in traditional methods.The Vector-spectrum is a joint name of vector spectrum and its patulous analysis methods, they fuse the double channels' information and remain the meanings of corresponding traditional methods. The Vector spectrum and it's patulous methods are only used to analyze stationary signals now. But the nonstationary signal is the mainly fault signal. So it's necessary to extend the Vector-spectrum analysis to nonstationary signal processing. Here, supported by National Natural Science Foundation of China (No.50675209), Innovative Foundation for the palmary Talents by Henan technology office (No.0621000500) and the Key technology Project of Henan (No.0122022000) , the Vector-spectrum analysis is extended to two mainly methods in nonstationary signal processing , the Wigner distribution and Ambiguity Function. And the method in nonstationary signal processing which is based on full information is proposed. The main content is as follows:1. Here, the Vector-spectrum analysis is extended to the Wigner distribution, a new signal processing method, i.e. vector Wigner distribution, is proposed to overcome the incomplete of Wigner distribution from the single channel and uncertainty of energy analysis. In this paper, the definition and algorithm of the vector Wigner distribution is introduced, and the proposed method is simulated and tested. The experiment result shows the proposed method is effective. The interference caused by cross-terms in wigner distribution.2. Combined vector spectrum theory with ambiguity function, a new concept, i.e. vector ambiguity function (VAF) is presented. The defined VAF inherits the advantages of vector spectrum and ambiguity function, i.e. it can reflect more comprehensive information of machine vibration and restrict effectively the interference caused by cross-terms in wigner distribution. Here, the definition, algorithm and characteristics of VAF are discussed, and this method has been successfully applied to fault diagnosis of rotating machine. Simulation and experiments results show that the defined vector ambiguity function is very effective in the fault diagnosis of rotor system , vector ambiguity function is superior to the vector Wigner distribution.3. The fractional Fourier transform (FRFT), which is a version of generalized common Fourier transform (FFT) can overcome the incomplete of FFT in feature extraction of fault signal. FRFT also reveals the features of signal from time and frequency simultaneously. In this paper, combined Wigner distribution with The fractional Fourier transform (FRFT), a new Wigner distribution based on Fractional Fourier transform(FRFT)is presented. And the Vector-spectrum analysis is extended to the new Wigner distribution which is based on Fractional Fourier transform (FRFT). The definition, feature and algorithm of the new method is introduced. Then the method is applied to the diagnosis of rolling bearing. The result shows that the method does work.