Research Of Gear Fault Feature Extraction And Noise Harmonious Based On Wavelet Transform And Fractal Theory

As a kind of physical pollution, noise pollution differs from other pollution. It comes while sound source starts to work and disappears while it stops without accumulation. However, noise pollution is always one of the most severe environment pollution, because of multitudinous sound resource and people exposed. So it is a heavy task to controls all kinds of noise pollution. With the development of modern industry and the improvement of people's living standard, more and more machine equipments,conveyance and home appliances appears. In the field of mechanical engineering, noise of mechanism is not only the main part of industry noise but also one of the most important quality symbols, which influences the value of equipment directly.As a source and a result, vibration and noise has a close relationship. Noise comes from vibration, so there is noise while there is vibration. Vibration and noise contain abundant information, which reflects state of equipment, and provides powerful accesses to diagnose. Fault signature signal is submerged by high frequency and noise, it is difficult to distinguish the fault signature signal from high frequency vibration and noise by classical power spectrum because it is lack of immunity to noise and have a thick skin to feeble fault signature signal. So the reliability and accuracy of diagnose is influenced. Moreover, controlling noise is not equal to decrease it, so we must consider the quality of sound besides decreasing noise. Traditional noise control mainly focus on reducing the damage to human ear by decrease noise. But it is difficult to go on decreasing noise in many aspects, in the same time, some sound level is not high enough to damage audition but the noise can create a disagreeable, confused and disturb feel, which means the sound quality is bad. In the modern society, where people want more and more high level of sound, sound quality is more important than sound level. So we must found out a system can depict sound quality based on human ear audition, i.e. subjectively appraise system.This research is supported by the scientific research item"the research on the viewable measurement and analysis system of acoustical holography"from China Ministry of Education, and the research item"The research of new detect and control method on the harmony of the noise of gear box"from Chongqing Education bureau. Large amounts of theory researches and corresponding experiments have been made. The research object is the noise of gear wheel, and the research route is:characteristic of...