Adaptive Redundant Multiwavelet Packet and its Application for Compound Faults Detection of Mechanical Equipment

It is significant to detect the fault type and assess the fault level as early as possible for avoiding catastrophic accidents. The compound faults detection of mechanical equipment is a challenge task at present. Thereby, it is urgent to develop a novel and effective method for this task. Multiwavelet with two or more base functions and many excellent properties may match two or more features of compound faults. In order to realize the accurate location and detection of the compound faults features, a novel method called adaptive redundant multiwavelet packet (ARMP) is proposed based on the two-scale similarity transforms in this paper. Moreover, the ratio of relative energy at the characteristic frequency of the concerned component is computed to select the sensitive frequency bands of multiwavelet packet coefficients. The proposed method is applied to analyze the compound faults of rolling element bearing with a local spalling on outer race and a slight scrape on the inner race. The results show that the proposed method could enhance the ability of compound faults detection of mechanical equipment.