Study On Acoustic Emission Signal Of Porcelain By All Phase Time-Frequency Domains Analysis

Porcelain is everywhere in our lives and is also used widely. But the quality detection of porcelain was technically immature in our country:The cost has been prodigious and the operation has a long circulating period. So detecting the quality of porcelain rapidly and accurately is pressing for solution. AE testing is one of the effective nondestructive detections. But the spectrum leakage by traditional signal truncation method in interrupting the digital signal and the shortcommings of Fourier Transform hinder the precise detecting seriously.This paper distinguishes which quality of porcelain is superior by All Phase Time—Frequency analysis of acoustic emission signal. As for the spectrum leakage by traditional signal truncation method in interrupting the signal, the All Phase signal interrupt method somewhat reduce this leakage which affects the follow-up porcelain quality discrimination, because All Phase signal interrupt method considers all cases containing a certain sampling spot. The simulation of processing porcelain AE signal by All Phase method shows that spectrum leakage is weaker and more accurate than that of traditional method. It establishes a solid foundation to the follow-up detecting the quality of porcelain by Time-Frequency domains analysis.Because Fourier Transform discomposes signals into different frequency component in its totality, lacks of Locality and do not give the duration of the spectrum. And the shortcommings are most acute in analysing sound signal which is No-Stationary signal. This paper analyses sound signal by Time-Frequency domains analysis containing STFT Time frequency Analysis and quadratic form Time-Frequency analysis. The STFT Time frequency Analysis comparing with window function in different length. And the quadratic form Time-Frequency analysis comparing with different Kernel functions. On the basis of a great simulations, I find Appropriate window function and Kernel function. I carry out experiments of different quality detections of porcelain combined with Euclid distance measure algorithm. The accuracy was98%.and satisfactory results are obtained.The method which is mentioned in this paper solve the problem of the quality detection of porcelain successfully by a great of experiments and simulations.It may be technical basis of the quality detection of porcelain in workshop.