Abstract:

Road slopes significantly affect vehicles’ fuel economy. This paper presents a novel Eco Speed
algorithm for vehicles on roads with up-down slopes based on road gradient information, which is the basic for
eco-driving assistance system with connected vehicles. Based on the construction of the vehicle model and the
fuel consumption model, the algorithm first calculated a steady eco speed, which is the most fuel economical
cruise velocity for a vehicle on the road without slopes. When entering a road slope, with the aid of GPS (global
positioning system) / GIS (geographic information system) information, the algorithm calculated the eco speed
profile, using dynamic programming. The algorithm was evaluated under Carsim and Matlab/Simulink, and the
simulation results show that the fuel consumption is reduced.

Key words: eco-driving, connected vehicles, driving assistance system, road gradient information, speed optimization, dynamic programming