Biodynamic response and body interactions with the seat pan and the back rest under vertical vibration

Enhancement of driver comfort related to vibration environment of road vehicles involves characterization of vibration environment, biodynamic response of the driver and seating dynamics. The human driver's responses, when exposed to automotive vibration along the vertical axis, have been widely characterized, assuming body interactions with the seat pan alone. The standardized ranges reported in ISO-5982 (2001) are considered applicable for human occupants seated on a flat pan with no back support. Moreover, the data used in the synthesis are believed to correspond to relatively high magnitudes of vertical vibration. The sitting postures in automotive seats are known to be considerably different from those considered in the standard and the reported data. Most importantly, the human drivers exposed to vertical vibration exhibit significant simultaneous interactions with the backrest. In this dissertation research, the body interactions with both the seat pan and the backrest are investigated under vertical automotive vibration and representative posture. An experiment design is realized on the basis of typical automotive seat to characterize the biodynamic interactions at the seat pan and the backrest. The measured data are analyzed to illustrate the significance of the seated body weight, magnitude of vertical vibration and a few posture-related factors, namely, the hands position and feet position. The results suggest strong influence of the body mass and built, and the hands position, and most of all significant interactions with the backrest