Laplace小波相关滤波法与冲击响应提取

Extraction of Impulse Response Based on Correlation Filtering Method of Lapalace Wavelet

冲击响应信号的出现标志着机械设备发生松动、碰撞、冲击等故障。在复杂的振动信号中准确提取出冲击响应信息在机械故障诊断中具有重要的意义。介绍了用来识别冲击响应信号的 L aplace小波相关滤波法 ,通过对含有噪声的模拟冲击响应信号的识别 ,证明该方法能够在强大噪声干扰中准确捕捉到冲击响应信号。工程应用结果表明 ,相关滤波法可以从复杂的内燃机缸盖振动信号中准确定位进气阀关闭时冲击发生的时刻及频率 。

The occurrence of impulse response in vibration signal means that there exist mechanical faults, such as looseness, shock, flaking and craze etc. It is important to exactly extract impulse response information from complex vibration signals for mechanical fault diagnosis. A method of correlation filtering is introduced based on the Laplace wavelet to identify impulse response in vibration signals. The results of simulation testing demonstrate that the correlation filtering method possesses high sensitivity for the identification of the impulse response in vibration signal that has violent noise. As a successful application, the moment and frequency of impulse response caused by the impact shut off of intake valve are extracted accurately from the vibration signal of the cylinder head of an internal combustion engine. So, the wear fault of intake valve is detected