Performance Guarantees for Hazard Based Lateral Vehicle Control

Today's vehicles are incorporating many advanced driver as- sistance systems and in the near future it will be likely to have increased capabilities such as lanekeeping assist systems. These systems will be an integral part of the driving experience, aid- ing the driver in avoiding hazardous obstacles. One approach for these systems is to represent the hazards as artificial poten- tial fields that add control inputs to move the vehicle towards safe regions on the road. This paper focuses on bounding the lateral motion of a vehicle for a lanekeeping system. A Lya- punov approach is used where the bounding function consists of the artificial potential energy associated with the controller, the kinetic energy in the lateral and yaw modes, and energy terms that are dependent on vehicle heading. In order to achieve this bound, a condition has to be met for the lookahead distance and the location of the control force (which can also be interpreted as a condition on the decoupling of lateral and yaw modes). Us- ing this bound, a potential field gain can be chosen to guarantee collision avoidance with fixed lateral obstacles.