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Because of the advantages of excellent power, fuel economy and zero-emission characteristics, electric buses have been used widely as cities’ short-range commuter vehicles. However, the high-frequency noise becomes more prominent for the powertrain system of the electric bus due to the lack of noise masking effect for the traditional internal combustion engine. To improve the noise characteristic of electric bus powertrain, the identification of the main noise source of the powertrain is well needed. In this paper, the effects of the motor and transmission on the noise level of the electric bus powertrain have been studied using lead packaging method. The variations of acoustical power level of the powertrain according to different rotation speed and torque under the conditions of only motor covered and only transmission covered have been discussed.

Korea has promulgated its automated-vehicle specific law, in proactive consideration of developing marketable automated vehicles and thus possessing competitive edge in future competition. Correspondingly, market-friendly mechanisms for automated vehicles in China fall relatively much behind. The Korean law concerning automated driving can be suggestive, through careful analyses of basic provisions and administrative mechanisms therein, with regard to national guidelines for developing automated vehicles in China’s automated vehicles.

In recent truck applications, single-piece large-diameter propshafts, in lieu of two-piece propshafts, have become more prevalent to reduce cost and mass. These large-diameter props, however, amplify driveline radiated noise. The challenge presented is to optimize prop shaft modal tuning to achieve acceptable radiated noise levels. Historically, CAE methods and capabilities have not been able to accurately predict propshaft airborne noise making it impossible to cascade subsystem noise requirements needed to achieve desired vehicle level performance. As a result, late and costly changes can be needed to make a given vehicle commercially acceptable for N&V performance prior to launch. This paper will cover the development of a two-step CAE method to predict modal characteristics and airborne noise sensitivities of large-diameter single piece aluminum propshafts fitted with different liner treatments.

Hybrid vehicle, equipped power source not only gas engine but also motor, power electronics and differing types of transmissions, manifests more complicated/specific/exceptional NVH behaviors than that of gas powered vehicle, like parking engine start/stop for charging, EV mode traction/recuperation, mode switch, etc. On top of that, differing hybrid architecture exists, depending on number and location of motor and type of transmission, hence NVH features and related control strategies are highly likely to be different even under identical driving scenarios, as such, the holistic and deep insight into the NVH features and related control strategies are very meaningful for hybrid vehicle NVH performance refinement, and will expedite the process of vehicle NVH development.