Effects of vehicle seat dynamics on ride comfort assessment

This research involves the investigation of vehicle seat structural dynamics on prediction of subjective ride comfort. Previous studies have indicated fundamental seat resonance in the range of human sensitivity. In our test, seat possesses three (lateral, fore/aft, twisting) mode shapes below 80Hz. Although many standards have created subjective ride comfort criteria, they have been developed with dynamically rigid seats. It is therefore important to see if cur-rent standard test procedure is accurate. Seventeen healthy volunteers have participated in the experiment. The experiment was carried out in the form of paired comparison tests. Volun-teers were asked to compare different resonating ride segments with non-resonating ride segments in which measured frequency weighted R.M.S vibration intensity was kept con-stant. From this subjective survey, the results show that the twisting mode has higher level of discomfort perceived by volunteers even when the measured vibration magnitude was kept constant. This clearly shows that the method for ride comfort measurement according to standard may need some improvements and must take into consideration the structural dy-namics of the seat. This is due to current measurement systems' accelerometer locations and designs. This study aims to provide important experimental data to improve current test standards in the field of whole body vibration and ride comfort.