PMP-based collaborative optimization hybrid heavy-duty truck eco-adaptive cruise control

Given the lack of energy optimization and the decoupling of speed planning and energy management in conventional ACC for Hybrid-Electric Heavy-Duty Trucks (HEHDTs), this study proposes a unified co-optimization framework based on Pontryagin's Minimum Principle (PMP). This framework enables the tightly synchronized co-optimization of velocity trajectories, torque distribution, and mechanical braking. A substantive innovation is that the distance-dependent aerodynamic model is integrated as a state-dependent parameter directly into the Hamiltonian, rendering the fuel-saving benefits of the slipstream an intrinsic component of the optimal control solution. Combined with an intelligent mode-switching logic and a Variable Time Headway (VTH) model, the vehicle proactively regulates its following distance to harvest aerodynamic gains. Furthermore, the derivation of closed-form analytical solutions for the coupled problem effectively transforms complex dynamic optimization into instantaneous algebraic calculations. Simulation results demonstrate that the dynamic synergy between gap regulation and analytical torque distribution is the primary driver for efficiency enhancement, achieving significant fuel savings ranging from 8.79% to 11.35%.