An Optimal Control Approach to the Path Tracking Problem for an Automobile

The problem of determining the steering required for an automobile to follow a specified path is investigated using exact inverse and optimal control methods applied to simple linear and nonlinear vehicle models in lane-change maneuvers. The optimal control method results in solutions which provide for reasonably close tracking of the specified trajectories, but with reduced steering activity in comparison with what would be required for exact tracking, and also with less severe excursions in the slip angles, yaw rates and lateral accelerations. The results appear to be qualitatively consistent with the manner in which a real driver would react and the method could find applicability as a tool to compare the handling properties of different vehicles in a manner analogous to that of test drivers following a specified test course.