A passenger comfort controller for an autonomous ground vehicle

Trajectory-following controllers for autonomous ground vehicles must carefully consider the possibility of vehicle instability. Previous approaches have provided a reference velocity along with a trajectory to follow, and a supervisory controller selects low velocity if turns are anticipated. However, such an approach is not robust across different vehicle platforms, and does not take into account passenger comfort. This paper provides a controller and design methodology to couple an existing trajectory controller with a speed limiting controller, where the speed-limiting controller is created based on user driving data. The result is a controller that can be optimized using a set of linearized controllers, and which is also demonstrated to remain below the velocity/turnrate thresholds established by human drivers: a conservative approximation for stability thresholds to prevent rollovers and skidding. Analysis is performed on data gathered using velocities between 0-18 m/s gathered in driving on surface streets as well as maneuvers in an open area, to demonstrate the validity of the thresholds in various conditions.