基于改进时频谱分析方法的滚动轴承复合故障诊断

将基于循环平稳理论及2阶循环统计量的谱相关或谱相关密度分析方法加以改进，提出一种时频分析方法并将其用于滚动轴承发生复合故障时调制现象循环调制频率即故障特征频率的提取。通过对滚动轴承复合故障的仿真及实际实验振动数据进行分析，结果表明:与同时提取出调制频率和载频的传统包络解调谱分析方法不同，改进的谱分析方法可以只提取出调制频率，提取的谱结构分布具有更清晰的表达效果，从而为滚动轴承的复合故障特征提取提供一种方法。 

Fault diagnosis of rolling bearing'compound faults based on improved time-frequency spectrum analysis method

Based on the theory of cyclostationarity and two orders cyclic statistic for the spectrum correlation (SC) or spectrum correlation density (SCD),a time-frequency analysis method,namely improved spectrum correlation (ISC),was proposed and used in fault feature extraction of rolling bearing'compound fault.Results show that the proposed method can extract the modulated frequency only and has more intuitive advantage than the tradition al envelope demodulation spectrum method because the latter extracts the modulated frequency and carrier frequency simultaneously.The feasibility and effectiveness of proposed method are verified through simulation and experiment.