Vehicle trajectory optimization for hybrid vehicles taking into account battery state-of-charge

Hybrid vehicles are found to be one solution to reduce fuel consumption in the transportation sector. Eco-driving is a concept that is immediately applicable by drivers to improve the efficiency of their vehicle. In this work the potential of eco-driving for hybrid drive train vehicles is discussed. The operation of hybrid vehicles is strongly dependent on their energy management and therefore on battery state-of-charge. Here, the velocity trajectory will be optimized taking into account battery state-of-charge. The vehicle and its control strategy will be modeled to simulate its operation. Given constraints on distance, velocity and time the optimal velocity trajectory is computed using the dynamic programming method in a non-standard approach. The optimal operation of the vehicle is compared to standard driving with respect to fuel consumption and battery state-of-charge. The algorithm is applicable to any hybrid vehicle architecture and will be illustrated on the Toyota Prius II vehicle.