Metodologia para avaliação e determinação de índices de conforto acústico em engenharia automobilística

Abstract

A method leading to the evaluation of vibroacoustic comfort in motor cars is discussed. This area has been a crucial issue for the automotive industry, as a key factor in a market which has become increasingly demanding during the last years. Even though there has been a corresponding development dedicated to this issue there still a gap between vibroacoustic parameter determination and Comfort Quality parameters for motor cars. The present work represents a contribution where a correspondence between car parametrization and automotive comfort is the main objective. Five motor cars, part of the same automotive consumer class but different in make and model have been the chosen sample to provide the necessary data to analyse the proposed method. These vehicles have been tested in a variety of road and operational conditions where the measured conventional vibroacoustic parameters have been associated with the subjective opinion of the testers. The resulting data have been organised using psychoacoutics considerations and a purpose developed statistical method. As a result, a range of acoustic and vibration comfort indicators (ACI and VCI) has been obtained. These descriptors have been correlated to the road conditions, to the vehicle under test and its corresponding operational condition. The obtained figures have been organised in order to provide a reference for car designers and car comfort analysis. These data have also been compared with the standard practice currently in use in the car industry. Even though the proposed method has originated from the mentioned practice the use of the parameters, and particularly the way in which they are associated provides a new insight into this area. Parameters seldom if ever used in this area such as Kurtosis and the combined effect o vibration (body feel) and acoustic (hearing) parameters have been associated in a way that strongly indicates the need for modification in the standard procedures if proper design parameters are to be obtained.