Energy-optimal platoon catch-up in moving bottleneck framework

Truck platooning, where vehicles drive close together in order to reduce air drag, is a promising technology that is slowly reaching maturity. In order to fully exploit its potential, we will need to be able to efficiently form platoons enroute, while driving on the road, by having the vehicles adjust their speeds so that they catch-up and merge into a platoon. Since this means that the participating vehicles will have to deviate from their own optimal speed profiles, experiencing unpredicted disturbances caused by the surrounding traffic might lead to higher fuel consumption. Therefore, in order to increase the fuel savings and improve their predictability, we devise a control strategy that takes into account the traffic conditions and yields optimal catch-up speeds for both the leader and the follower vehicle. The control strategy is based on minimizing total energy consumption, and it models the vehicles as moving bottlenecks. We compare this strategy to one that does not consider the influence of traffic, and show that it achieves better results in terms of energy savings.

I. Introduction

Recent years have seen an accelerated push towards heavy-duty vehicle platooning [1], [2]. Traditionally, such platooning was primarily regarded as means of reducing the air drag acting on the vehicles [3], and thus fuel consumption, but there are also other benefits, like facilitating a higher level of automation. There has been much work done on controlling the vehicles inside a platoon [4], [5], and this technology is slowly transitioning from academia to industry. There are other aspects of platooning that still require more research, including how truck platoons influence traffic, how platoons should be formed, and how to make decisions on which vehicles should platoon with which other vehicles [6].