On the sound quality of the propulsion system in hybrid vehicles

Abstract

New targets of the automotive industry in reducing fuel consumption and environmental impact, while maintaining or even improving vehicle's performance, force the companies to migrate to new propulsion paradigms. The use of lightweight materials for building structural systems in conjunction with hybrid and/or electric propulsion systems may have a negative impact on the perception of the auditory phenomena at the passenger's cavity, as the internal combustion engine disturbance is no longer present, and the materials' low damping lead to the perception of undesired transitory and high-frequency disturbances, which deteriorate the sound quality of the vehicle. This study deals with the development of both numerical and experimental strategies for approaching the perceived sound quality at the passengers' cavity, during the operation of the propulsion system in hybrid/electric vehicles. Electrical-mechanical control systems will be implemented over the power driver signals commanding the electric motor, as their influence over both transient and high-frequency disturbances is widely demonstrated through the specialized literature. The use of synthesized and/or measured signals and systems allows characterizing of the auditory disturbance and the implementation of control schemes at the electric and/or mechanic domains. Calculation of relevant psychoacoustic metrics over the controlled disturbance will lead to validate the proposed theories and techniques in this paper. (AU)