Nonlinear-gain-optimized controller development and evaluation for automated emergency vehicle steering

Earlier research in advanced vehicle control systems (AVCS) has focused on automated lateral and headway control during low-g maneuvers. However, most emergency situations involve high-g maneuvers where vehicle performance becomes nonlinear. Robust controllers need to be developed that can react to these emergency situations. This paper investigates the development of a nonlinear-gain-optimized (NGO) controller for automated lateral control during emergencies. The strategy is to use a linear model to define the state model and a nonlinear model to optimize the feedback gains for high-g emergency maneuvers. The performance of the NGO controller is presented at 15 and 30 m/s for a step lane change and a double lane change. The NGO controller's robustness is investigated with respect to changes in tire parameters and the number of passengers.