Factor analysis of power seat noise using blocked force

In recent years, operating noise generated by various devices in cabin has been focused and becomes noise reduction target due to the reduction of vehicle running noise. In this study, we then conducted the noise evaluation and investigated the noise factors of a power seat at the operating condition. At first, the operating noise at around driver's ear position and vibration of the seat frame were measured using an artificial head microphones and acceleration sensors. As a result, the noise and vibration at 400-500 Hz band was found to be large and the reduction was essential to decrease the noise. Subsequently, Component TPA was applied to understand the main factor of the large vibration of the frame at the target frequency. The result shows the vibration was increased largely due to the resonance between the rotational order input force from the driving motor and the natural frequency of the frame. As an instance of the countermeasure, small weight was added to the resonated part of the frame to avoid the resonance and the vibration and noise was observed to decrease at the target frequency band.