Hierarchical control design of automated vehicles for multi-vehicle scenarios in roundabouts

Control design for safe and time-efficient motion of automated vehicles in roundabout scenarios poses various challenges, especially adaptation to the actual traffic scenario and coordination of the vehicles. This paper proposes the design of a hierarchical motion control with learning functionality for roundabout scenarios. The control is designed on two levels, such as on cloud level and on vehicle level. The control on the cloud level is designed by using reinforcement learning, with which the maximum speed for the vehicle is achieved. The vehicle level contains a robust controller and a supervisor, with which the collision avoidance of the vehicles is guaranteed. The proposed control on Hardware-in-the-Loop environment with small-scaled indoor vehicles is implemented. The effectiveness of the control and the safe motion of the automated vehicle under various scenarios are demonstrated. The provided scenarios illustrate that safe, i.e., collision-free motion of the automated vehicle can be guaranteed, even if the connection to the cloud has been lost.