Hierarchical Velocity Control Considering Traffic Signal Timings for Connected Vehicles

Velocity profile optimization using upcoming signal information of urban vehicles is one of the main eco-driving techniques, which can significantly enhance the capability of reducing idling fuel loss and trip time. This paper proposes a hierarchical velocity control system considering different drive preferences for connected and automated vehicles to improve overall efficiency under the vehicle-to-X (V2X) environment. Two major contributions are (i) control-oriented formulation of task planning in multiple road segments, which is amiable to numerical computation and can consider different drive preferences; and (ii) solving the nonlinear velocity trajectory optimization to realize real-time control in the lower level. Simulation results indicate that energy-saving and computational efficiency are improved using the proposed control system. The solution algorithm is further demonstrated under a hardware-in-the-loop simulation.