Battery aging-aware speed planning and energy management for autonomous hybrid electric buses at signalized intersections and bus stations

Abstract

Autonomous hybrid electric buses (A-HEBs) are equipped with multiple energy sources, and the co-optimization of speed planning and energy management strategy (EMS) for them plays a key role in reducing fuel consumption, emissions, and traffic congestion. Incorporating battery aging into EMS can also extend battery lifespan. To this end, this paper proposes a traverse model predictive control (TMPC) strategy for battery aging-aware speed planning and EMS in scenarios with multiple intersections and bus stations. First, the reference speed of the A-HEB is calculated based on traffic light and bus station information. Then, the battery state of charge (SOC) is planned, and the TMPC is developed by accounting for economy, comfort, traffic efficiency, and battery aging. The results show that the TMPC enables the bus to pass through intersections without stopping and to stop smoothly at stations. The TMPC effectively prevents excessive battery discharge and temperature rise, reducing the battery aging cost by approximately 11.96% and the overall economic cost by about 1.73% compared with the TMPC without considering battery aging. Additionally, the TMPC achieves better overall performance than a layered strategy. Finally, the real-time performance of the TMPC is verified through a hardware-in-the-loop experiment.