包络变形对阶比分析结果的影响及消除方法

转速变化的滚动轴承故障诊断通常先采用计算阶比跟踪技术消除变转速的影响，再进行阶比分析获得故障特征。然而，等角度重采样会引起冲击包络变形进而导致阶比分析结果产生偏差，在转速变化范围较大时这个偏差必须要受到重视。本文的主要工作是介绍了等角度重采样方法，仿真了包络变形对阶比分析结果的影响，给出了峰值点间隔变化量详细的理论推导，提出了通过修正角度变换值来消除包络变形影响的方法，并进行了实验验证。研究结果显示，包络在宽窄方向的变形对阶比分析结果没有影响；相邻包络峰值点间隔的变化对阶比分析结果产生影响；在角度序列逐点减去峰值点间隔变化量可消除包络变形对阶比分析结果的影响。

Effects and its elimination method of envelope deformation on order analysis

Defects diagnosis of rolling element bearings operating under time-varying rotational speeds entails order tracking and analysis techniques that convert a vibration signal from the time domain to the angle domain to eliminate the effect of speed variations. Angular domain re-sampling will induce shock envelope deformation leading to errors of the analysis, and the effect is particularly noteworthy when the rate of speed change is significant. This paper presents a quantitative analysis of key factors affecting the accuracy of order analysis on rotating machines with varying speeds. An analytical model is established, simulated, and experimentally evaluated. Eliminating methods are proposed for which the angle value should be modified by removing the peak interval variations. The research findings show that deformation of the envelope in the width direction has no effect on results of the order analysis; interval variations of adjacent envelope peak have influence on the results of the order analysis; removing the peak interval variations in angle sequence can eliminate the effects of envelope deformation.