EFFECTS OF MODEL COMPLEXITY ON THE PERFORMANCE OF AUTOMATED VEHICLE STEERING CONTROLLERS - CONTROLLER DEVELOPMENT AND EVALUATION

Due to increased traffic congestion and travel times, research in Adva nced Vehicle Control Systems (AVCS) has focused on automated lateral a nd headway control. Automated vehicles are seen as a way to increase f reeway capacity and vehicle speeds while reducing accidents due to hum an error. Recent research in automated lateral control has focused on vehicle control during low-g maneuvers. To increase safety, automated lateral controllers will need to recognize and react to emergency situ ations. This paper investigates the effects of vehicle and tire model order on the response of automated vehicles to an emergency step lane change using a controller based on linear vehicle and tire models. Fro m these studies it is concluded that control strategies based solely o n linear vehicle and tire models are inadequate for emergency vehicle maneuvers. A strategy is then proposed to automatically control vehicl es through emergency maneuvers. Here the response of a nonlinear vehic le model is used with a linear state model to optimize controller gain s for nonlinear maneuvers. An emergency step lane change is used as a preliminary test of the method.