An optimized driving comfort with a low interior noise level is an important intention in the passenger car development process. The interior noise level caused by the dynamic interaction between the rolling tyre and the rough road surface and transmitted via the car-body is a significant component of the entire noise level. To reduce the road induced interior noise, in general, the chassis system has to be optimized. Passive measures often induces a trade-off between vehicle dynamics and driving comfort. To overcome this disadvantage in this paper, the development and realization of an active measure is proposed. For the purpose of active mechanical decoupling, an active control system is developed, the feasibility of the integration is investigated and its noise reduction potential is identified by vehicle tests. In a first step, a classical multi-channel and experimental-based structure-borne transfer path analysis of the full vehicle is realized to determine the dominant transfer paths. The concept for the active mount system (active mounts, multi-channel control system, sensors) is developed and parametrized by system level simulation. Mechanical components and power electronics of the active system are designed, manufactured and tested in the laboratory. Subsequently, the entire active system is integrated into the vehicle. The broadband adaptive feedforward algorithm is extended by certain measures in order to improve robustness and performance. Full vehicle tests are used to quantify the required specifications and the achieved effectiveness of the active vibration control system.

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Within the contact zone between tire and road all normal and tangential forces have to be transmitted. The tread block is the only tire component which is in direct contact to the pavement and therefore of special interest. The rolling process of a tire can be seen as a chronology of single contact events between tread block and road surface, whereas the contact situation in detail is usually unknown. The surface texture of the pavement comprises a large range of surface wavelengths which leads to a small area of real contact and to complex contact conditions. Under braking and acceleration procedures sliding friction occurs within the footprint especially at the trailing area of the contact zone. The tangential forces strongly depend on the contact conditions, e.g., surface texture, sliding velocity, normal contact pressure, temperature, tread block geometry, and existence of a lubrication film. An intermediate layer not only simply lowers the friction coefficient but also the whole contact situation changes. This effect is considerably existent for siped tire tread blocks which react in a different manner compared to nonsiped tread blocks. Within this publication the dynamics of siped tread blocks in contact are analyzed and a mechanical model will be presented to explain the observed phenomena. The simulation results are verified by experiments.

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