基于小波变换的汽车空气流量计信号去噪

Vehicle Mass Air Flow Signal De-noising Based on Wavelet Transform

根据发动机空气流量计信号的特征，在Matlab中，选用Daubechies五阶正交小波（db5）对含噪的MAF信号进行4层小波分解，再对分解后得到的各层系数用软阈值法量化处理，最后利用小波重构，实现对信号去噪，并将去噪信号运用于实车试验。试验表明，小波变换对MAF信号具有良好的抑噪效果。

According to the characteristic of MAF（ Mass Air Flow）, the MAF signal with noise is decomposed to 4 layer with wavelet named Daubechies （ db5 ） in Matlab. After decomposing, the soft-threshold de-noising method is adopted to eliminate noise, then use the inverse wavelet transform to reconstruct signals for signal de-noising. The test results show that this method can eliminate the noises of MAF effectively.