A MPV Interior Booming Noise Test Analysis And Control

The NVH performance of vehicle means noise, vibration and harshness experienced by passengers under the working conditions of the vehicle. NVH is a comprehensive index for automobile quality evaluation, which can be felt by customers in the most intuitive way. Harshness, namely the quality of the noise and vibration of vehicle, is a subjective feeling of vibration and noise when driving a car. So it can’t be evaluated by objective test parameters. Also, some academics call the harshness as no ride comfort or shock resistance, etc.First of all, the analysis and control of vehicle noise are introduced at home and abroad. The main noise sources of the vehicle are analyzed. This article describes the general characteristics and mechanism of booming noise. The subjective and objective evaluation method of vehicle noise is analyzed. Research is mainly focused on the method of noise reduction, especially the roaring noise.Secondly, combined with a company encountering the problem of MPV’s too loud noise, the reason of noise has been analyzed by large number of experiments. Besides, this article identifies the path of the booming noise. The effect of the local modes of the vehicle body and the torsional vibration of the drive system on the roaring noise of the vehicle is confirmed.Thirdly, the vehicle driveline components are simplified. According to establishing model and calculation of simplified driveline, it gets the inertia parameters and stiffness parameters of driveline. A simulation model of driveline is established with AMESim software. Free vibration of driveline is calculated in AMESim software. Then, the torsional vibration modal characteristics in each order are obtained. According to the comparison between simulation results and experimental results, this article verifies that the simulation results are effective.Finally, based on the simulation model of driveline, the influence of torsional vibration modal frequency and torsional vibration response of the driveline installed with metallic inertial plate was analyzed. According to the reasons of booming noise, the local structure of vehicle body and the parameters of the driveline have been improved to reduce the booming noise. Experimental results show that two kinds of noise reduction schemes can effectively reduce the vehicle interior noise. The vehicle NVH performance is improved under acceleration condition.The method of decreased the multi-purpose vehicle interior booming noise was proposed and it can be used for reference for the development of similar vehicle.