Development of a new eyellipse and seating accommodation model for trucks and buses

Abstract

Driver posture data from a laboratory study and an in-vehicle test-track study were used to develop and to evaluate a new seating accommodation model and eyellipse for SAE Class-B vehicles. The new statistical models are configurable for population anthropometry; include the effects of steering wheel position; incorporate a new method based on driver preference for using the adjustment range of highly adjustable steering wheels as input to the models; and are customizable to any desired accommodation level. The new seating accommodation model predicts ranges of fore-aft seat-position that are similar to those in SAE J1517, but includes simultaneous prediction of vertical seat adjustment range. The new eyellipse is almost twice as tall as the current J941 Class-B eyellipse, due to the incorporation of vertical seat adjustment. The new eyellipse is narrower in plan view and aligned with the vehicle grid, unlike the J941 eyellipse. Predictions from the new model compared well with driver seat positions and eye locations measured in six test vehicles, although extensive seat-position censoring in four of the test vehicles limited the comparison. The new models are more accurate and much more flexible for application to modern trucks and buses with vertically adjustable seats and tilt/telescope steering columns.