Eco-driving of fuel cell electric trucks: optimal speed planning combining dynamic programming and Pontryagin's minimum principle

Abstract

Eco-driving is an energy-aware driving style that improves the overall vehicle efficiency to reduce operating costs and extend the driving range. This paper focuses on the eco-driving of fuel cell electric trucks, optimizing the speed plan based on the route elevation, and studying the trade-off between driving time and range. In particular, the optimal speed plan is created by combining two methods from optimal control theory (dynamic programming and Pontryagin's minimum principle) to include an energy management strategy for fuel consumption optimization. The speed plan created with the proposed method increases the vehicle range by 8\% compared with a constant speed plan. Moreover, the study shows that the vehicle range can be extended up to 50\% if the driving time is increased, which might be an essential solution to cope with the undeveloped hydrogen refueling infrastructure. The conclusion of this work indicates several directions to continue the research on the topic: for example, addressing robustness to traffic conditions and including component degradation mitigation targets in the optimization (e.g. SoC operating range and fuel cell voltage degradation).