Application of a robust steering controller in emergency situations

In typical highway driving conditions, a collision between two closely following vehicles can result in significant deviation and rotation in vehicle movements. These motions in turn may lead to devastating consequences with other surrounding vehicles. To mitigate the seriousness of such accidents, it would be beneficial to provide a lane-tracking function that helps maintain proper vehicle trajectories once a collision occurs. The paper describes a feasibility study of applying steering control in vehicle-following collisions. When vehicles are involved in a collision, they experience sudden changes in their state variables, such as speed and yaw rate. Therefore, the control efforts in these situations must be effective enough to stabilize the vehicle trajectories under the impulsive disturbances created by a collision. A generic look-ahead controller was used in the feasibility study. The selected control law, using feedback information of lateral position and yaw angle, corrects the current and foreseen deviation from the desired position. The collision scenarios evaluated in the paper include trajectory following on straight and curved roads. To account for factors in real-world situations, potential steering-wheel offset due to collision damage and time delay in sensing and actuation cycles are included in the evaluation. The controller was found to be effective in various situations. The feedback controller utilized in the study illustrates a simple yet robust control law that can be applied to a wide range of system conditions. The result is significant because a robust controller is essential to such applications when a system is open to uncertainties and variations in operation parameters. The implementation of a robust controller in the described scenarios can potentially provide driver-assistance or an automated function in vehicle safety systems.