Optimal Connected Cruise Control with Arbitrary Communication Delays

Connected cruise control (CCC), as an approach to regulate vehicle's longitudinal motion in car-following platoon scenarios, can improve the safety and efficiency of the traffic flow. In order to make it available for extensive information sharing among vehicles, wireless vehicle-to-vehicle (V2V) communication is exploited in the vehicular platoon. However, time delays caused by wireless communication may result in significant degradation of system stability. In this article, considering arbitrary V2V communication delays, an optimal longitudinal control algorithm is proposed for the CCC vehicle with the goal of minimizing the deviations of vehicle's headway and velocity. In the proposed scheme, the vehicular platoon is modeled as a discrete-time system based on vehicle's error dynamics, and the optimal-state feedback control problem is designed as a cost function represented by a sum of platoon states in a quadratic form. A backward recursion method is used to iteratively derive the optimal control strategy, namely the acceleration for CCC vehicle, based on the current platoon states and previous control signals. In addition, the stability analysis shows that the system is asymptotically mean square stable under the control of the proposed algorithm. Finally, numerical simulations indicate that the proposed algorithm provides better system performance and stability.