Society of Automotive Engineers (SAE) Recommended Practice J941 describes the eyellipse, a statistical representation of driver eye locations. Eye position data collected recently at University of Michigan Transportation Research Institute (UMTRI) suggest that the SAE J941 practice could be improved. SAE J941 currently uses the SgRP (vehicle seating reference point) location, seat track travel (L23), and design seatback angle (L40) as inputs to the eyellipse model. However, UMTRI data show that the characteristics of empirical eyellipses can be predicted more accurately using seat height, steering wheel position, and seat track rise. A series of UMTRI studies collected eye location data from groups of 50 to 120 drivers with statures spanning over 97 percent of the United States population. Data were collected in thirty-three vehicles. Significant and consistent differences were observed between eye position data collected before and after driving, indicating that actual driving is an important protocol feature for accurate measurement of driver eye position. In six vehicles, eyellipses obtained with two-way and six-way seat track travel were only slightly different. On average, drivers select seatback angles that are about 1.6 degrees more upright than design seatback angles. Stepwise regression techniques were used to identify the vehicle variables that have important effects on the distribution of driver eye locations. (A)
Samenvatting