A tour of the Hilbert-Huang transform: An empirical tool for signal analysis

The HHT provides an alternative tool for signal analysis. Case studies in applying the HHT technique for bearing degradation monitoring and machine tool breakage detection have demonstrated its effectiveness for revealing the non-stationary and non-linear features hidden in dynamic signals. In addition to the application illustrated in this article, the HHT technique has shown to be effective in other applications such as biomedical engineering [8], [9], system identifi cation [10], [11], environmental monitoring [12], or fi nancial analysis [13]. Because of its empirical nature, rigorous mathematical proof of this technique has remained an active research topic. More interesting reports are to be expected on the application of this technique for solving various types of real-world problems. © 2007 IEEE.