Dynamic timing warping (DTW) is a useful method in speech recognition [10]. Two-time series can be distinguished by comparing the distance between them. In this progress, the two-time series will be matched in order to minimize the distance which signifies the degree of difference between the two series. There are many similarities between speech and vibration, thus, the DTW algorithm was introduced into the field of condition assessment and some preliminary effects have been achieved [11]–[13]. Furthermore, the shortcomings of this algorithm including excessive match [14] and distance calculation [15] are under research.