A Method to Improve an Electric Vehicle's Range: Efficient Cruise Control

This article proposes a method to improve the range of an Electric Vehicle (EV) by controlling its speed depending on the upcoming traffic signal status. A conventional Adaptive Cruise Control (ACC) controls an EV's speed such that there is a certain distance between the EV and the preceding vehicle. However, if the preceding vehicle drives at a non-optimum speed given the upcoming traffic signal status, as it nears the upcoming traffic signal the preceding vehicle will have to dissipate the unnecessarily gained kinetic energy by braking. If the EV blindly follows such a preceding vehicle using a conventional ACC, the EV will also have to dissipate a part of its kinetic energy by braking. In this work, this problem is addressed by proposing an Efficient Cruise Control (ECC). In the proposed ECC, if the EV is within a certain distance of the upcoming traffic signal, its speed reference is calculated based on the traffic signal status, while maintaining a minimum safe inter-vehicular distance from the preceding vehicle. The ECC is designed using Model Predictive Control theory and it is studied in a simulation environment using a Tesla S vehicle model. The simulation results show that the proposed controller improves the EV's energy efficiency and therefore range, where the latter is an important bottleneck in widespread adoption of EVs