Utilizing Road Grade Preview For Increasing Fuel Economy of Hybrid Vehicles

This paper evaluates the potential gain in fuel economy of a hybrid vehicle, if terrain preview is predictively utilized in the vehicle's energy management. The optimal energy management strategy is calculated numerically when future grade is known and for different known cruise velocities. The resulting fuel economies are compared to those of baseline strategies without preview. Simulations over real-world hilly roads shows a potential for up to 6 percent improvement in fuel economy. It is shown that this level of improvement depends on the cruise speed, the control strategy, and the road profile.