基于滑动统计特征的信号非平稳度评价和比较

Evaluation and Comparison of Nonstationary Signals Based on Moving Statistical Characteristics

对多种典型的信号整体和局部非平稳度计算方法及其局限性进行比较,在此基础上根据滑动统计分析的思想提出滑动均值、滑动方差以及滑动变异系数的概念和计算方法,以充分表征信号的时变细节和不同信号的差异。针对不同的机械故障信号和心电信号,对不同算法的平稳度评价能力和适用范围进行分析和比较。结果表明,相对于传统评价方法,基于滑动统计特征的信号非平稳度评价方法具有较突出的理论基础、精度和稳定性。

Nonstationarity is an important characteristic to represent the randomness and the variability of engineering signal,and its quantification and evaluation are the effective bases for signal analysis and pattern recognition.The typical calculation algorithms of the global non-stationary and local non-stationary are demonstrated and compared.Based on moving statistical analysis,the concept and algorithms of moving mean value,moving variance and moving variation coefficient are proposed,in order to fully characterize the varying details in time domain and the diversity of different signals.By the nonstationarity analysis of different mechanical fault signals and electrocardiogram signals,the evaluation capability and applicability of different algorithms are analyzed and compared.The results indicate that the moving statistics method has outstanding theoretical foundation,precision and stability in the evaluation method of nonstationarity.