Abstract
Ultra-compact EVs are becoming increasingly popular recently. Therefore, it is important to provide ride comfort for a driver to advance the high-value-adds of automobiles. However, one of the problems for the ultra-compact EV, an interior noise caused by road and wind noise have a large impact on user comfort in the interior space. Especially, the noise reduction of low frequency noise like a load noise is difficult by passive noise reduction technique using noise reduction material. Therefore, the use of interior noise reduction by active noise control (ANC) has been widely performed in the automobile industry. We proposed ANC system whereby a giant magnetostrictive actuator which is one of small actuator is installed on the roof of the ultra-compact EV. In this paper, we conducted a noise reduction experiment installed the giant magnetostrictive actuator on plate shaped part of the ultra-compact EV by using single-frequency sound waves in the frequency range of the road noise. In addition, we investigated the installation position of the giant magnetostrictive actuator considering the vibration characteristics of the roof to improve the noise reduction effect. From these results, we considered that it is necessary to change the installation position of the actuator according to the output frequency. Furthermore, we proved that it is important to consider the vibration characteristics of the plate shaped part on the actuator to obtain a high noise reduction effect.
