Abstract:

Speed advisory systems have been used for connected vehicles to optimize energy consumption. However, for their practical utilization, presence of preceding vehicles and signals must be taken into account. Moreover, for Battery Electric Vehicles (BEVs), factors that deteriorate battery’s life cycle and discharging time must also be considered. This paper proposes an eco-driving control for connected BEV with traffic signals and other safety constraints. Traffic signals are considered as interior point constraints, while inter-vehicle distance with preceding vehicles, vehicle speed and battery charging/discharging limits, are considered as state safety constraints. Backward-forward simulator based Speed Guidance Model is applied to follow the optimized velocity under powertrain safety limitations. Effectiveness of the proposed methodology is tested on a 5.3-km route in Islamabad, Pakistan. Real traffic data using Simulation of Urban Mobility under different driving scenarios is considered. Using the proposed method, around 21% energy can be saved compared to the preceding vehicles that followed their random velocities under the same traffic and route conditions. This means the EV controlled by the proposed method can have longer driving range. Furthermore, the host BEV has crossed signals during their green time without collision with preceding vehicles. Low charging rates and terminal Depth of Discharge indicate less number of charging cycles, thus proving the usefulness of the proposed solution as battery’s lifesaving strategy.

Key words: Eco-driving, First-order Thevenin model, Inter-vehicle safety constraint, Interior point constraints