Experimentally Establishing Ideal Platooning Performance as a Metric for Real-World Platooning Assessment 2022-01-0069

Platooning heavy-duty trucks decreases aerodynamic drag for following trucks, reducing energy consumption, and increasing both range and mileage. Previous platooning experimentation has demonstrated fuel economy benefits in two-, three-, and four-truck configurations. However, exogenous variables disturb the ability of these platoons to maintain the desired formation, causing an accordion effect within the platoon and reducing energy benefits via acceleration/deceleration events. This phenomenon is increasingly exacerbated as platoon size and road grade variations increase. The current work assesses how platoon size, road curvature, and road grade influence platoon energy efficiency. Fuel consumption rate is experimentally quantified for four heterogeneous Class 8 vehicles operating in standalone (baseline), two-, and four-truck platooning configurations to assess fuel consumption changes while driving through diverse road conditions. Platooning was accomplished via PID-based Cooperative Adaptive Cruise Control (CACC). The four heterogeneous trucks were operated at the National Center for Asphalt Technology (NCAT) oval track and the American Center for Mobility (ACM) freeway loop. An “ideal” platooning case is established to quantify the maximum energy efficiency of each platoon configuration utilizing straight sections of the NCAT track, which contain trivial grade changes and complete alignment of all platooning vehicles. Platoon energy efficiency benefits while operating over the grade and curvature variations of the ACM track are then compared against the ideal platooning benefits to isolate the influence of road grade and curvature on energy efficiency. The hypothesis for this study is if road grade variance (measured by standard deviation) increases for a drive cycle, then the fuel consumption for any given vehicle on that drive cycle will increase.