小波变换在摆式列车倾摆控制系统故障诊断中的应用研究

RESEARCH ON WAVELET TRANSFORM TO FAULT DIAGNOSIS IN TILTING CONTROL SYSTEM OF TILTING TRAIN

小波变换在故障诊断中得到较广泛的应用 ,但采用不同的小波 ,分析结果往往会有很大差异。对常用的正交、半正交、双正交小波提取信号特征的能力进行分析比较 ,表明半正交B样条小波因具有线性相位和采用较长的分解系列 ,而具有较好的频域局部化特性和较小的变换误差 ,是摆式列车倾摆控制系统故障诊断中的较佳小波基。提出一种新的确定故障诊断阈值的方法 ,并通过实验证明了方法的有效性 ,为小波变换在摆式列车实车倾摆控制系统故障诊断中的应用提供理论依据。

Most of a signal information is often carried by signal singularities which may be caused by fault in system. Theory of singularities detection can provide a relation between signal singularities and the wavelet transform modulus maxima. The application of practical wavelet transform in fault diagnosis is growing rapidly. There are many different wavelets to use but no accepted procedure for choosing among them. The results of them have great difference. So it is very difficult to select a wavelet for a particular problem. The characteristics of orthogonal wavelet, semi orthogonal wavelet and biorthogonal wavelet in signal decomposition and reconstruction are compared, and the results of the study demonstrate that B spline wavelet that has linear phase filtering and good time frequency localization, can be applied to fault diagnosis in tilting control system of tilting train. It is show that B spline wavelet has many advantages over other wavelets and has the broad application prospect in the domain of fault diagnosis. Therefore it is a good wavelet for fault diagnosis in tilting control system of titling train. A new approach is proposed for deciding the fault threshold, which is decided by the multiplication of high frequency band signal of wavelet decomposition. The favorable results are obtained through the experiment of tilting control system. It is confirmed that the method can be applied in fault diagnosis in tilting control system of tilting train successfully. The theoretical foundation of using wavelet transform to fault diagnosis in tilting control system of reality tilting train is presented.