Energy-Efficient Cooperative Adaptive Cruise Control for Electric Vehicle Platooning

Cooperative adaptive cruise control (CACC) can optimize velocity planning by interaction between connected vehicles, and thus increase energy efficiency. It is much significant for platoon of electric vehicles (EVs) powered by hybrid energy storage system (HESS). HESS which is composed of battery and supercapacitor (SC), has been implemented to improve energy efficiency by regulating the distribution of internal energy sources. Different from most existing works on energy management for EVs, this paper is concerned with a bi-level control strategy for platoon's velocity planning and HESS management. The upper layer focuses on the cooperative velocity planning for platoon to guarantee internal stability of individual vehicle and platoon robust string stability. The optimal velocities for each vehicle in the platoon could be determined by using distributed model predictive control (DMPC) method. The safety condition and the constraint on communication delay are considered. In the lower layer, a rolling horizon optimization method is proposed to optimize the power of HESS with the assistance of planned velocities in the upper layer. The simulation results indicate the effectiveness of the proposed strategy and methods.