Impact of Mixed Traffic on the Energy Savings of a Truck Platoon 2020-01-0679
A two-truck platooning system was tested on a closed test track in a variety of realistic traffic and transient operating scenarios - conditions that truck platoons are likely to face on real highways. The fuel consumption for both trucks in the platoon was measured using the SAE J1321 gravimetric procedure as well as calibrated J1939 instantaneous fuel rate, serving as proxies to evaluate the impact of aerodynamic drag-reduction under constant-speed conditions. These measurements demonstrate the effects of: cut-in and cut-out maneuvers by other vehicles, transient traffic, the use of mismatched platooned vehicles (van trailer mixed with flatbed trailer), platoon following another truck with adaptive cruise control (ACC) and the presence of a multiple-passenger-vehicle pattern ahead of and adjacent to the platoon. These scenarios are intended to address the possibility of “background aerodynamic platooning” impacting realized savings on public roads. Using calibrated J1939 fuel rate analysis, fuel savings for curved track sections vs straight track sections was also evaluated for these scenarios. The presence of passenger-vehicle traffic patterns had a measurable impact on platoon performance, but the basic fuel savings trends were retained. At large separation distance, the use of the manufacturer-installed ACC demonstrated similar fuel savings to the use of the cooperative-ACC (CACC) platooning system at the same distance, while also providing additional benefit to a following platoon.
Brian McAuliffe, Arash Raeesi, Michael Lammert, Patrick Smith, Mark Hoffman, David Bevly
National Research Council Canada, National Renewable Energy Laboratory, Auburn University