一种适用于非平稳、非线性振动信号分析方法研究

Hilbert-Huang变换(HHT)被认为近年来信号分析领域的一大突破。适用于非平稳、非线性信号分析。从往复机械上得到的振动信号往往具有非平稳、非线性特征，因此采用HHT方法分析是一种较佳的选择。然而，该方法提出不久，并不能用一个解析公式表示，影响了对其理论分析及性能评价。建立一多分量仿真信号，并应用HHT、傅里叶变换、小波变换、时频分布对其分析比较，证明它具有较高的分解效率及准确地刻画信号的能力，并由此发展了能消除多分量信号交叉干扰项的时频分析方法。应用HHT对内燃机敲缸信号进行分析，有效地提取故障的特征信息，为往复机械的状态监测及故障诊断提供了一条有效途径。

A suitable analysis method for nonlinear and non-stationary signal

Hilbert-Huang Transform(HHT) is regarded as a breakthrough method in the signal analysis domain. It is suitable to analyze nonlinear and non-stationary data. The vibration signal from the reciprocating engine is non-stationary, time-variation, so, application of HHT is a good choice. However, the technique cannot be expressed by an analytical formulation so that it is difficult to conduct theoretical analysis and performance evaluation. A multicompomnet signal was built. And then, compared with the Fast Fourier Transform(FFT) and Wavelet Transform(WT) and Wigner-Ville Distribution(WVD), HHT has the capability of the high efficient decomposition signal and accurately describing it, by which a reducing cross terms interference Time-Frequency Distribution(TFD) method was developed. Applying of HHT to analyze knock cylinder signal, result shows that it can effectively extract fault signal characteristic information and give a way of the condition monitoring and fault diagnosis for reciprocating machinery.