Look-ahead cruise control for heavy duty vehicle platooning

Abstract

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 to pography. The focus of this study is to establish whether it is more fuel-ef fi cient 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.

Cooperative Look-Ahead Control for Fuel-Efficient and Safe Heavy-Duty Vehicle Platooning

“…Slopes become more critical in the case of HDVs driving in a platoon formation. In [8], the authors point out how the existing look-ahead strategies for single HDVs are not necessarily suitable for a platoon and that a dedicated approach is required. This is due to the fact that the additional requirement of keeping a small inter-vehicular distance between vehicles collides with the fact that HDVs experience significantly different longitudinal forces (e.g., gravity force depending on their mass and current road slope and air drag resistance depending on the distance from the previous vehicle).…”

Cyber–Physical Control of Road Freight Transport

“…As it is well-known that standard policies for specifying the inter-vehicular distance in a platoon are not compatible with tracking a spatially varying reference velocity profile [5], [10], we adopt the delay-based spacing policy…”

Control of platoons of heavy-duty vehicles using a delay-based spacing policy∗∗This research is funded by the FP7 Programme of the European Union through the project COMPANION.

“…However, it is clear that follower vehicles might be required to have a higher velocity on this hill (i.e., at the same location in space) when they are subject to a constant spacing or constant headway policy. This might be infeasible due to limited engine power and leads to undesired platoon behavior, as recognized in Alam et al (2013) and Turri et al (2014).…”