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

Recent research in Advanced Vehicle Control Systems (AVCS) has focused on automated lateral and headway control during low-g manoeuvres. However, most emergencies involve high-g manoeuvres where vehicle performance becomes nonlinear. Robust controllers need to he developed that can react to these. emergencies. This paper investigates development of a nonlinear-gain-optimised (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 optimise feedback gains for high-g emergency manoeuvres. Performance of the NGO controller is presented at 15 and 30 m/s for a step lane change, a double lane change, and inward and outward lane changes initiated during a non-banked 0.1 g turn. The NGO controller's robustness is investigated with respect to changes in tyre parameters and passenger numbers.