Failure analysis of transmission devices using self-organizing map

In this paper, a general failure analysis method of transmission devices is proposed. First, we record the acoustic signals of good and no good transmission devices in operation. Then we decompose the acoustic signals by using wavelet transform. From all the components of signal, we select the significant component, which corresponds to the specified failure, based on the reconstructed signal, while setting the lower level wavelet approximation to zero. Next, we compute the frequency characteristic of the significant component and use the self-organizing map (SOM) to classify the specified no good products from the good and other no good products. By comparing the difference between the groups of specified no good products and good products, we can estimate the cause of trouble. Furthermore, while an unknown product is inputted to the SOM network, we can determine whether the inputted product has the specified failure. The experimental results show that the proposed method can perform the failure analysis of transmission devices successfully.