Driver steering assistance for lane departure avoidance

In this paper, a steering assistance system is designed and experimentally tested on a prototype passenger vehicle. Its main goal is to avoid lane departures when the driver has a lapse of attention. Based on a concept linking Lyapunov theory with linear matrix inequalities (LMI) optimization, the following important features are ensured during the assistance intervention: the vehicle remains within the lane borders while converging towards the centerline, and the torque control input and the vehicle dynamics are limited to safe values to ensure the passengers' comfort. Because the steering assistance takes action only if necessary, two activation strategies have been proposed. Both activation strategies were tested on the prototype vehicle and were assessed as appropriate. However, the second strategy showed better reactivity in case of rapid drifting out of the lane. (C) 2008 Elsevier Ltd. All rights reserved.