盲系统辨识与故障诊断

Blind system identification and fault diagnosis

盲系统辨识是一种仅由系统的输出中提取系统的未知信息的一种新的基本信号处理方法.论述了盲系统辨识的基本思想及其算法,将盲系统辨识思想引入到旋转机械状态监测与故障诊断中,提出了基于盲系统辨识的机械故障诊断的方法,并以转子裂纹为例,研究了基于时序模型盲辨识的不同的裂纹位置、深度的转子裂纹参数化双谱特性,得到了一些有价值的结论,为转子裂纹的诊断提供了一种新的方法.实验结果表明,该方法是有效的,基于时序模型盲辨识的参数化双谱分析具有对故障的灵敏性及能显示检测信号的一次、二次谐波等主谐波以及描述检测信号中二次相位耦合等非线性现象.

Blind system identification (BSI) is a fundamental signal processing technology, which retrieves a system's unknown information from its output only. The basic idea of blind system identification and its algorithms are discussed. The method of machine fault diagnosis based on BSI are presented. Through experiment research of a cracked rotor, the bispectrum characteristics of the cracked rotor with different crack depth and crack location were investigated using blind identification method of time series model. Some valuable conclusions were obtained, and a new approach for the diagnosis of cracked rotors was provided. The experiment results show that this approach is very efficient. The bispectrum analysis based on blind identification of time series model is sensitive to fault; displays the first, second and higher harmonics of the signal, and describes nonlinear phenomena such as second phase coupling.