Look-ahead cruise control for heavy duty vehicle platooning

Vehicle platooning has become important for the vehicle industry. Yet conclusive results with respect to the fuel reduction possibilities of platooning remain unclear, in particular when considering constraints imposed by the topography. The focus of this study is to establish whether it is more fuel-efficient to maintain or to split a platoon that is facing steep uphill and downhill segments. Two commercial controllers, an adaptive cruise controller and a look-ahead cruise controller, are evaluated and alternative novel control strategies are proposed. The results show that an improved fuel-efficiency can be obtained by maintaining the platoon throughout a hill. Hence, a cooperative control strategy based on preview information is presented, which initiates the change in velocity at a specific point in the road for all vehicles rather than simultaneously changing the velocity to maintain the spacing. A fuel reduction of up to 14% can be obtained over a steep downhill segment and a more subtle benefit of 0.7% improvement over an uphill segment with the proposed controller, compared to the combination of the commercially available cruise controller and adaptive cruise controller that could be used for platooning. The findings show that it is both fuel-efficient and desirable in practice to consider preview information of the topography in the control strategy.