Research On Indoor Measurement Method Of Noise Emitted By Accelerating Road Vehicles

Vehicles accelerating passing-by noise?PBN?is an important basis for evaluating NVH performance of a vehicle.However,since the International Organization for Standardization issued the international standard ISO 362-1:2007 for vehicles accelerating passing-by noise measurement,several problems,such as the higher testing requirements,the increase of difficulty in measurement and the lower qualification ratio of data,have appeared.These problems have puzzled the technicians and engineers in outdoor surveying.In order to reduce the difficulty of testing and improve the success rate of testing,this paper carries out the research of indoor equivalent testing method.First,a scientific and rigorous indoor test flow of passing-by noise is established,and the indoor PBN noise signal is measured under the time signal synthetic algorithm.Besides,the appropriate tire noise model is selected,and the indoor and outdoor tire sliding test is carried out on the outdoor measured field and the indoor low-noise chassis dynamometer,and the indoor and outdoor tire noise curves are fitted.Finally,the principle is superimposed on the sound pressure level,and the indoor tire noise is subtracted from the indoor noise signal,and the outdoor tire noise of the same model is added to obtain the indoor noise equivalent value.If the error between the indoor equivalent value and the outdoor measured value is within 1dB?A?,it is proved that the indoor and outdoor equivalent replacement is completed.The indoor noise equivalent test method is applied to a certain M₂ manual gear A car and a M₂ automatic gear B car.The results show that the error between the indoor equivalent value and the outdoor measured value of the two vehicle categories is within1dB?A?,and over 40%testing time is saved,which is of high engineering application value.