Research On Cab Noise Source Identification And Control Of Wheel Loader Based On RobustICA

Noise pollution hazard is such serious a problem that it become one of the major environment issues of concern after air pollution and water pollution. Along with the development of construction machinery industry, the construction noise problem seriously affects people's life, the operator's physical and mental health hazard. There is no doubt that the implementation of new national standards on noise limits has brought a new pressure to the entire domestic construction machinery industry. This research is based on college-enterprise cooperation project “Reasearch on the key techonlogy of noise control of wheel loader”. Noise source identification and contribution analysis was carried out, proposed reasonable and effective noise control strategy to reduce the cab noise of wheel loader. It is of great engineering application value.This paper found the features of the loader indoor noise through the formulation and implementation of targeted testing schemes. Discussed the extraction performance of robust independent component analysis(Robust ICA), which is better than Fast ICA. The corresponding physical noise source of indoor noise was found by the method that combine RobustICA and continuous wavelet transform(CWT). Wavelet packet was used to do contribution analysis and determined the main cab noise source. Formulate the corresponding noise reduction measures, and verified the effect.The driver ear noise sound pressure level of the target wheel loader is 87.4dB(A). This number meet the current national standard for the first phase limits(89 dB(A)), but can't meet the second phase limits(86dB(A)) that will be implemented in 2015. Outdoor air noise mainly leaks into the cabin inside through the cabin wall holes and seams. The driver ear noise is mainly made up of low frequency components less than 1000 Hz.The superior extraction performance of Robust ICA was validated by simulation signal, and the cabin noise source identification was carried out combined with the wavelet analysis. The main noise source of the cab is determined through wavelet packet analysis and f contribution degree analysis.According to the results of the sound source identification, purposeful noise control measures was carried out on the target wheel loader. Result show that the cab drivers ear sound pressure level is lower than the the second phase limits of the national standard with the control measures, meet the noise reduction purpose.The results show that the Robust ICA is effectively in noise source identification, provided technical support for engineering mechanical noise control. Controling the main noise sources and improving cab sealing performance can effectively reduce the cabin noise.