瞬态信号波形重构及其应用

Waveform Reconstruction of Transient Signal and Its Application

振动监测由于设备简单，处理迅速，是实现机械系统早期故障检测的有效方法之一瞬态信号由于其频率范围较宽，持续时间短，易受到传递路径和其它噪声的影响谱分析很难判别机器的状态，倒谱滤波技术，作为一种非线性滤波技术，不但可以实现卷积信号的分离，而且通过选择适当的窗函数，消除结构混响，强化信号特征本文从理论和方法上论述了倒谱强化滤波技术以及瞬态信号复原的实施步骤，并利用该技术和最优化技术，进行气缸压力时间曲线的恢复。

Monitoring using vibrational signals has been recognized as one of the valid methods for detecting early faults in mechanical systems because of the simplicity of devices used and fast-processing.Transient signals,because of the broad range of frequencies and short time duration,can be easily affected by structrual transmission and noise.Cepstral filtering,as a nonlinear filtering technology,can separate the convoluted signals,but also effectively remove the structural reverberation to intensify the features of signals by selecting a suitable window function.This paper theoretically and practically discusses the procedure for reconstruction of transient signay the use of cepstral filtering.Furthermore,this procedure com bined with optimum is used to recover time history waveform of cylinder pressure in a diesel engine in order to realize the engine condition monitoring without demounting.