Denoising Method Study on Automobile Engines Based on Wavelet Packet Transform

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.