【摘要】 利用小波包变换理论及小波包降噪原理,对汽车发动机含有噪信号进行小波包降噪,有效的提取其中的信号特征。通过对降噪后残差的频谱分析和统计量分析,得到噪声信号的特征频率。通过计算机仿真和实例分析对小波包降噪方法进行验证,表明小波包分析在汽车发动机降噪中有效性。更多还原

【Abstract】 Using the theory of wavelet packet transform and its de-noising principle,de-noising of the signals of automobile engines was carried out and analyzed.And the signal characteristics were extracted effectively.Through the residual signal spectrum analysis and statistics analysis after de-noising,the characteristic frequency of the noise signal was obtained.Finally,through the computer simulation of several examples,the wavelet packet de-noising method was verified.The result shows that wavelet packet de-noising method is very effective.更多还原