Energy-efficient cooperative eco-driving and energy management of extended-range electric heavy-duty truck platoons with spacing-dependent aerodynamic coupling

Improving the energy efficiency of heavy-duty freight transportation is important for reducing fuel consumption and carbon emissions. This paper proposes an analytical hierarchical optimization framework for cooperative eco-driving and energy management of extended-range electric heavy-duty truck (ERE-HDT) platoons on continuously undulating roads. In the upper layer, slope-preview speed planning for the leading vehicle and cooperative car-following for following vehicles are integrated into a unified formulation. A spacing-dependent aerodynamic coupling model is embedded to characterize the propagation from inter-vehicle spacing and wake drag reduction to traction power demand and energy management. Through dynamic convexification and quadratic programming (QP) reformulation, the coupled multi-vehicle speed planning problem is converted into an analytically solvable form. In the lower layer, mode decoupling and control-variable reconstruction transform range extender–battery power allocation into a convex QP problem with analytical equivalent factors. A discrete forward coordination mechanism is further used to ensure implementability under speed, spacing, power, and state of charge (SOC) constraints. Simulation results show that the proposed method reduces total equivalent fuel consumption by 4.69% compared with the baseline strategy and by 5.09% compared with the constant-Cd ablation strategy. Compared with the offline dynamic programming (DP) reference, fuel consumption is only 3.90% higher, while computation time decreases from 307.630 s to 2.211 s.