Research On Noise Control Of Vehicle Based On Sound Intensity Technology

With the continuous development of the modern automobile industry, vehicle noise has become a major component of the traffic noise and urban ambient noise, and this makes the task of vehicle noise control to be particularly important and urgent. To control the vehicle noise, the most primary thing is to find the main noise source conveniently and quickly so that we can find apt and specific ways to solve the problems. Currently used method for vehicle main noise source identification has a higher demand for measuring environment, as well as the measuring period is long and the price of the measuring instruments is high. Therefore, it is of great significance and use-value to develop a set of measuring system with simple structure, easy operation and low-cost.Based on the basic theory of sound intensity and the theory of signal analysis and processing, this article adopts the virtual instrument development platform, develops a set of noise sound intensity measurement system which is of simple structure and easy to use, identifying the main noise source of vehicle with sound intensity method. The main work for research as follows:1) Making use of sound intensity probe, data acquisition cards, signal conditioning equipment and computer to realize the package design for the hardware system in the sound intensity measuring system ;2) Based on LabVIEW virtual instrument development platform, a data acquisition module, a data open and storage module, a time domain analysis module, a frequency-domain analysis module, a sound intensity calculation and spectral analysis module, a 1 / 3 octave module and a result display module is developed;3) Taking bus noise as the test subject, conducting noise measuring tests on it, and inputting measuring data into the data processing module to obtain the three-dimensional map of sound intensity and isacoustic chart, from which the location of the main noise source is found. Then determining that the main noise sources for this vehicle in order were engine mechanical noise, exhaust muffler noise and cooling fan noise. According to this, corresponding improvement on these parts is made, and the expected noise reduction results are achieved.Work done above is a useful exploration to our vehicle noise control and accumulates some practical experience for the research of sound intensity measuring technique on noise measurements, which will lay a good foundation for the further work in this area later.