故障信号

With regard to the software design, we realized the software filter for anti-intermixing; and we use the Fast Fourier Transform Algorithm to analyze the harmonic of the voltage and current; also we analyze the method of calculating all the parameters of the power system, fault component and positive, negative, zero sequence.

软件算法方面，系统对信号采用了抗混叠软件滤波，并采用传统的快速傅立叶变换，对采样的电压和电流信号进行频谱分析。论文中还详细分析了电网各参数，故障分量以及正、负、零序分量的计算。

By projecting signals with different frequencies into the subspace I, the signal with the supply frequency has the maximum value. Consequently, in the spectrum of the reciprocal of the projecting value, the supply frequency component is cut off and the fault feature component emerges in the spectrum.

把不同频率的信号投影到子空间I，基频信号在该空间的投影将远大于其他的频率分量，因此在投影的倒数谱中，基频分量被抑制，凸显出了故障频率分量。

It is introduced in the feature extraction of the vibration signal induced from reciprocating machinery valve,and t.

该方法用于往复机械气阀的振动信号特征提取，有效地提取了气阀的故障特征信号。

This method takes account of the signal's properties of statistical distribution and wavelet space time-frequency distribution.

在第八章给出了应用实例，能有效分离倍频机械信号，和水力脉动的低频信号，为故障诊断提供依据。

The system collects and saves running state signals and these signals are diagnosed by fault diagnosis expert program. Then diagnosis results are sent to display screen in order to instruct trainman to keep locomotive running safety.

该系统采集并存储机车运行状态信号，由故障诊断专家程序对信号进行诊断，并将诊断结果发送到显示屏指导乘务员维护机车安全运行。

It is, therefore, tailor mode for analyzing the signal such as a fault travelling wave.

而小波变换具有在时域、频域表征信号局部特征等性质，它适合检测故障行波这样的突变信号。

Presignal processors: finishing head for processing the data signals from the chip, the chip such as the problem may be not be able to correctly identify the phenomenon of hard disk failure.

前置信号处理器：用于加工整理磁头芯片传来的数据信号，该芯片如出现问题可能会出现不能正确识别硬盘的故障现象。

Though analyzing and studying the following conclusions are gotten:(1) The fault features can be extracted from the unstably and stably vibrant signals in different extents by the methods of STFT, WPARMS and SOCS effectively (2) The acceleration signals not only possess far higher signal-noise rate of feature information than that of the stable, but also conceal the feature information which has not in the stable signals.

通过分析与研究，得出了如下结论：(1)短时Fourier变换、小波包AR谱、二阶循环谱均能有效处理发动机稳态和非稳态振动信号。它们都能在不同程度上提取出包含在振动信号中分析对象的故障特征。

This method makes full use of of small commutation fall function of a confusion of voices and experience mode decompose get used to cent to explain ability oneself, can bona fide reflects signal feature, offerred a kind of feasible way to be based on the breakdown that signal analyses to diagnose.

该方法充分利用小波变换的降噪功能和经验模式分解的自适应分解能力，能真实地反映信号特征，为基于信号分析的故障诊断提供了一种可行的途径。

From the original signal of"ladder type" undercut, it is difficult to find out the exception, through observing the undercut signal by means of the"focalizing scanning"of wavelet transform in time-frequency domain, the fault features are accurately extracted. The results reveal that this method has flexibility to the variation of tool diameters, tooth of cutter and cutting parameters.

在&阶梯型&过切的原始信号上几乎看不出信号有明显异常现象，在时频空间采用小波分析方法&聚焦式&扫描观察&阶梯型&过切信息，能准确地提取过切的故障特征，研究表明，该方法对刀具直径、刀具齿数及切削参数的改变有较强的适应性。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。