Platooning electrified trucks: Benefits of saving energy and minimizing emissions

This paper aims to minimize energy consumption and reduce tailpipe emissions of truck platooning, and analyzes the effects of powertrain electrification levels to maximize platooning benefits under real-world driving conditions. To this end, this study develops an innovative hierarchical energy and emission management control framework that integrates different powertrain electrification levels with platooning strategies. A nonlinear model predictive controller (MPC) at the upper level ensures safe inter-vehicle spacing and promotes smooth speed trajectories, while a lower-level MPC optimizes the propulsion commands to track the upper-level torque demand and minimize energy consumption. The controller additionally mitigates engine transients to minimize tailpipe nitrogen oxides (NOx) emissions. Homogeneous truck platoons with diesel, pre-transmission parallel hybrid electric (P2), plug-in hybrid electric (PHEV), and battery electric (BEV) configurations are evaluated by leveraging experimental data collected during the truck platooning trials on public roads. The results show that the proposed control framework effectively maintains safe spacing across all time gaps and improves follower performance through coordinated speed smoothing and torque optimization. Among the configurations considered, the PHEV follower achieves the largest benefit, with up to 6% reduced equivalent energy consumption and 36% lower tailpipe NOx emissions, even at a 5-sec time gap on the Alberta Highway 2 drive cycle. Overall, the results demonstrate that the proposed hierarchical platoon–powertrain control strategy can deliver simultaneous energy and emissions benefits for electrified truck platooning under realistic long-haul driving conditions.