Road noise sensitivity analysis with respect to suspension geometry

In the vehicle development, the importance of reducing road noise is increasing because of the increasing popularity of quiet electric vehicle. The suspension plays an important role on the mechanism of the structure born road noise. As the countermeasure for reducing road noise, low stiffness suspension bush is often used from the point of view of vibration insulation. However, in general, to use the low stiffness suspension bush makes the driving stability worse. From such reason, it has been difficult to achieve the compatibility between NVH and driving stability at high quality. Therefore, the other ways are required for reducing the road noise. As one of the ways, the road noise reduction by the suspension geometry is presented in this paper. In order to find the suspension geometry which reduces the road noise, the sensitivity analysis is used. For the sensitivity analysis with respect to the position of the suspension arm connecting points, the suspension model is simplified. The arms are modeled as rigid links whereas the vehicle body, tire and shock absorber are modeled as a modal model. The suspension geometry which reduces the road noise is obtained with the sensitivity analysis.