A Sound Synthesis Model for Sound-Quality Optimisationof Starting Electric Railbound Vehicles

摘要

In recent years, research activities and sound-abatement measures in the field of electric railbound vehicles (e.g. trams, subways and light-rail vehicles) have been mostly concentrated on rolling noise. However, some additional noise components often play an important role, especiallyduring the starting procedure of modern vehicles. Among them, one can point out the motor inconnection with the traction converter as well as other sources such as the gear coupling. The acousticoptimisation potential of this kind of noise, called 'traction noise', is rather unknown. Therefore, astudy is actually carried out in order to find out those sound-generating parameters which are criticalfrom a psychoacoustic point of view (e.g. the switching sequence or the gear teeth number). The most important step of this work is to identify a set of technical parameters that make traction noise sound as pleasant as possible. In order to avoid extensive parameter studies on real vehicles, a simplified acoustic model is developed which comprises synthesized traction-noise components and added real rolling-noise components. It provides an acoustical reproduction of a wide range of vehicles. It is shown that the synthesized sounds are hardly distinguishable from real recordings. Finally, some first results of optimisation studies are presented.