OPERATOR' PERCEPTIONS OF TILT ANGLE IN AGRICULTURAL OFF-ROAD VEHICLES

Roll-over incidents are the major cause of fatalities, resulting in the death of novice operators as well as lifelong operators, of several off-road vehicles used to carry out different tasks on farms. Accurate perceptions of tilt angle are considered vital in helping operators to avoid situations that may lead to an overturn, but investigations suggest operators are not adept at predicting an overturn because of the number of factors they must track and analyze. Penn State Department of Agricultural and Biological Engineering developed a simulator to study side tilting angle operators' perception on agricultural tractors. The same equipment has been later used for investigation in perception of stability of all-terrain vehicles (ATVs) drivers. The presentation describes the studies carried out using the simulator to investigate for both vehicles the ability of operators to correctly evaluate slopes, the mean slope angle at which the most and least conservative operators indicate a beginning of concern of a roll-over, and to compare operators' estimated angles with the actual tilt angles, and reports the main results of the studies.