Objectives and content
Quality and comfort of transportation means are - to a considerable extent - assessed by cabin noise to which passengers are exposed. The disturbing primary noise sources are the combustion engine (cars, ships), wheel-surface interaction (trains, cars) and inter-cabin noise (ships). For airborne noise the transmission loss increases with the mass of the panels. The use of light-weight panels is on the other hand very important: manufacturing costs, fuel consumption and cargo capacity depend on the weight of the vehicle. The need for comfort obstructs the need for light-weight panels.
The main industrial objective of the research is to demonstrate a major breakthrough in the development of active noise control systems, which can on the other hand increase the comfort and reduce the weight in transportation systems. This can be achieved by using high efficient flat film actuators as anti-noise sources.
The new technical innovation, electro-mechanically treated film (EMF) can be used as an acoustic source. The actuators made of EMF are very thin, weigh very little, are mass-producible and thus cheap and can be placed on all desired places along panels. In existing cabins noise reduction using ANC can be more efficient and extended to higher frequencies. In future transportation systems light-weight panels on which the film is fixed can have acoustic transmission loss as high as the transmission loss of existing high-weight panels.
The easy integration of low-cost EMF-actuators in ANC system can make the ANC systems extremely feasible in the control of low frequency noise. The main drawback with older ANC systems have been that they have not been compatible with mass-production and the price of the systems have been high.
The technical objectives of the research are to investigate, design and develop two prototypes for active noise control systems in which EMF-transducers (combined sensors and actuators) are used as anti-noise sources.
The first prototype is a hybrid multiple-input multiple-output ANC system comprising cells of EMF-actuators as anti-noise sources. The system will be applied to reduce periodic noise in cabins. If required, for the very low frequencies, a small number of loudspeakers (typically 2) may be added.
The second prototype is a light-weight panel on which (isolated) actively controlled film cells are fixed to increase the transmission loss of the panel. The system will be used to increase the transmission loss for stochastic cabin noise.
The demonstration of an effective ANC system in transportation systems will disseminate the technique also to other sectors for instance to building acoustics, household appliance noise contorl and even to industrial machinery noise control.
Funding SchemeCSC - Cost-sharing contracts
10043 Orbassano Torino
2628 CK Delft