Fundamental Study of Time Domain Contribution Separation Technique for Principal Component Mode Affecting the Ride Comfort of a Vehicle

Reduction of low frequency vibration during running is essential to improve the ride comfort of a vehicle. Especially, when a transient input is given to the vehicle, vibration analysis in time domain had better to be done to grasp the phenomenon deteriorating the ride comfort. In addition, finding out the parts having high contribution to the ride comfort and taking countermeasures to the part is effective way to improve the ride comfort. Operational transfer path analysis (OTPA) has been proposed as a method for extracting the high contribution parts or the vibration modes of the target structure to the vehicle interior noise and vibration at the running condition. However, this method was originally developed to apply frequency domain vibration signals. In this study, we thus attempted to modify the recently proposed OTPA method focusing principal component to be able to analyze time domain signals for obtaining the high contributing PC mode to the transient phenomenon. In the test, small simple vehicle body model was employed and the method was applied to the vibration signals in the operational condition. As the result, high contributing vehicle body vibration behavior (PC mode) to the transient vibration phenomenon of the vehicle was found out.