Abstract:Aiming at the difficulty of efficiency and cost in deep hole quality inspection, a method using vibration signal segmentation and improved dynamic time warping (DTW) is proposed to test deep hole peck drilling quality quickly. Firstly, the vibration signal of peck drilling is segmented by the double window bispectrum algorithm with excellent anti-noise performance. Secondly, features of the sub-signal are extracted after segmentation in the time and frequency domain for dimensionality reduction. Then, there being the unequal length of feature vector caused by sub-signal, an improved DTW is used to perform regular alignment, reduce the time complexity and prevent ill-conditioned regularity. Eventually, the similarity between the sub-signals is represented by the cumulative shortest distance, so as to determine whether the quality of the corresponding hole segment of the sub-signal is abnormal. The simulation and experimental results show that the method can detect the quality of deep hole machining quickly and effectively, and the analysis results of the vibration signal is consistent with the actual physical inspection, which shows the reliability and practicability of the method.