The Green City Car. A holistic approach for NVH abatement of city cars

Pursuing the different passive and active concepts in a holistic approach, the FP7 project Green City Car demonstrates the feasibility of applying active systems to NVH-related problems light city cars from a system point-of view. During the project, a city car equipped with a small engine has been considered equipped with the latest technology in terms of safety aspects related to pedestrian's impact and car-to-car compatibility, which are of major importance in an urban environment. The noise reduction technology developed and implemented in this city car addressed the mass reduction of the complete sound packages, the application of new materials, passive or active piezo-electric or electro-magnetic patches on vehicle and engine panels, smart Helmholtz resonators and broadband active noise cancellation. A complete integration and correct balance of such components should be found out, in order to achieve the given objectives of noise and weight reduction. Within this paper selected results achieved within Green City Car will be presented and discussed.