The present study investigated the effectiveness of a continuous lateral control support via an active steering wheel during driving on a German freeway. The continuous steering support was realized as an off-target augmented feedback by superimposing artificial torque on the regular steering torque. A Heading Control system permitting various control strategies calculated an "optimal" steering wheel angle. If the driver's input deviated from this steering wheel angle, an additional steering wheel torque was generated proportional to this difference. This torque change indicated that the driver should re-adjust his lateral control behavior. The field study, conducted on an 80 km stretch of a German freeway, was designed in order to evaluate the driver's lateral control performance and strategy with three different control strategy conditions for the optimal steering wheel angle under two task demand conditions. Thirty two male subjects were instructed to drive the instrumented car as normally as possible with a recommended speed of 100 km/h in low volume traffic. The results show the usefulness of a continuous steering wheel support which is due to the workload reduction when compared with driving without steering support. (A)
Samenvatting