关键词: 多尺度排列熵, 偏均值, 液压泵, 故障特征

Abstract:

A permutation entropy was introduced into the fault diagnosis procedure of hydraulic pump and its ability to distinguish different faults was analyzed herein.The mutual  information and false nearest neighbor algorithm were used to select the delay time and embedding dimension independently, the permutation entropy which was based on the selected parameters had more excellent performance to distinguish the faults of hydraulic pump. Aiming at the shortages of permutation entropy only measuring the complexity of the vibration signals in only one scale, the partial mean of multi-scale permutation entropy which composited the value of multi-scale permutation entropy and its variation tendency was proposed based on the study of multi-scale permutation entropy, and it was used as a parameter to distinguish the difference of various faults of pump. The results of actual testing vibration signals demonstrate that the proposed parameter is more efficient and more excellent than that of traditional PE to distinguish the faults of hydraulic pump.

Key words: multi-scale permutation entropy(MPE);partial , mean;hydraulic pump;fault , feature