Abstract
This paper describes an experimental investigation of human perception of transient whole-body vibration by seated subjects. Thirty participants (25 male and 5 female) were asked to sit on a rigid seat and were exposed to combinations of 6 acceleration signals taken from experimental measurements made on a European B segment automobile. Longitudinal seat guide acceleration signals from a pave surface, a comfort test track and a motorway segment were used. The data was acquired at a sampling rate of 250 Hz and was bandpass filtered to be in the range form 0.5 to 50 Hz. The three road signals were rescaled to two reference r.m.s amplitudes of 0.6 m/s2 and 1.2 m/s2, thus providing a base set of six test signals. The 6 base signals were used to form 30 paired-comparison test signals consisting of two 15 second bursts of road data separated by a 2 second gap. The subjective information obtained from the participants was converted to a perception scale by means of Comparative Judgment Theory, and compared to the r.m.s. and the VDV values calculated for the 15 second road data bursts in both their unweighted and their ISO 2631 and BS 6841 frequency weighted forms. The frequency weighted measures, both r.m.s. and VDV, were found to provide a better estimate of human vibrational comfort than their unweighted equivalents, with the differences being most pronounced in the case of VDV values. While the data collected to date is limited, these preliminary results also suggest that the ISO 2631 and BS 6841 evaluation procedures overestimate the subjective discomfort at low excitation levels.