Road-tire induced vibrations are in many vehicles determining the interior noise levels in (semi-) constant speed driving. The understanding of the noise contributions of different connections of the suspension systems to the vehicle is essential in improvement of the isolation capabilities of the suspension- and body-structure. To identify these noise contributions, both the forces acting at the suspension-to-body connections points and the vibro-acoustic transfers from the connection points to the interior microphones are required.
In this paper different approaches to identify the forces are compared for their applicability to road noise analysis. First step for the force identification is the full vehicle operational measurement in which target responses (interior noise) and indicator responses (accelerations or other) are measured. Secondly, the operational data is used in different methods for force-identification: matrix inversion based, mount-stiffness based, or parametric force-identification.
The choice for each of those methods can be based on a suspension characteristic as the stiffness of the mounts, the available space for sensor instrumentation or other practical limitations.