Eco-Platooning for Cooperative Automated Vehicles Under Mixed Traffic Flow

The mixed traffic flow, which comprises both cooperative automated vehicles (CAVs) and human-driven vehicles, is becoming more common in modern urban areas. CAVs can expand the capabilities such as that can be achieved with automation and vehicular communication individually. However, the energy-saving benefits may be one of the exceptions when three or more vehicles drive in a row under the mixed traffic scenarios. The undesired driving behaviors of human-driven vehicles can introduce a high level of randomness to traffic flow, which results in energy-inefficient driving profiles for CAVs with aggressive operations or even vehicle crashing. In this paper, we investigate an eco-platooning problem for CAVs under the mixed traffic flow. This is a challenging problem due to both of the platoon-wide energy-saving and driving security requirements. To address this problem, an ecological and string stable platooning scheme, called E-CACC, is provided. First, novel spacing policies are presented to enforce that all platoon members track energy-efficient driving profiles. Then, control laws are designed to ensure the tracking performances of the proposed spacing policies. Furthermore, the theoretical proof is provided to prove the platoon string stability of the proposed strategy. Finally, performance evaluation is conducted. Results have illustrated the energy efficiency of the proposed E-CACC scheme.