Abstract
The present research studied about the noise reduction method based on the wave absorbing principle of the rolling noise which spreads over a seeable open space from the rail by the devices installed on the proof cover of railway vehicle. A device unit consists of one controller, one parabola-microphone and two plane-wave speakers. First, based on the acoustic numerical simulation analysis by using the 3-D Boundary Element Method, the methods of improving the previously proposed device construction concept were examined and then three kinds of new type devices were manufactured. And the fundamental characteristics of respective device were grasped experimentally. Then decentralized control experiments by using multi- device units which were estimated to be the best by the simulation and the above experiments were carried out and the method of improving the control effects of total system consisting of multi-device units was examined.
