Predicting vehicle ride comfort

Abstract

Laboratory experiments have shown that the discomfort caused by whole‐body vibration is highly dependent on the frequency, direction and duration of the vibration, the occurrence of impulses, and on the locations of the points of contact of the body with vibrating surfaces. The acceptability of vibration in vehicles depends on situational factors which vary over time and between vehicles. It must be recognized that vibration acceptability depends on these factors in addition to vibration intensity. The relative vibration discomfort in different vehicles can more easily be measured and predicted. The results of a series of laboratory experiments are used to define a general vibration discomfort prediction procedure which can be applied to seated subjects experiencing complex (random and impulsive) vibration occurring in up to twelve axes (three translational and three rotational axes on the supporting seat surface: three translational axes on the seat‐back, and three translational axes at the feet). It is shown how this procedure may be applied with time‐series analysis methods to determine the principal frequency components, axes, and vibration interfaces responsible for discomfort. The procedure may also be used for the evaluation of the vibration isolation provided by seating and other changes in vehicle design.