Ecological Cooperative and Adaptive Cruise Control (Eco-CACC) is widely focused to enhance sustainability of CACC. However, state-of-the-art Eco-CACC studies are still facing challenges in adopting on rolling terrain. Furthermore, they cannot ensure both ecology optimality and computational efficiency. Hence, this paper proposes a nonlinear optimal control based Eco-CACC controller. It has the following features: i) enhancing performance across rolling terrains by modeling in space domain; ii) enhancing fuel efficiency via globally optimizing all vehicle's fuel consumptions; iii) ensuring computational efficiency by developing a differential dynamic programming-based solving method for the non-linear optimal control problem; iv) ensuring string stability through theoretically proving and experimentally validating. The performance of the proposed Eco-CACC controller was evaluated. Results showed that the proposed Eco-CACC controller can improve average fuel saving by 37.67% at collector road and about 17.30% at major arterial.

翻译：生态协同自适应巡航控制（Eco-CACC）因其在提升CACC可持续性方面的重要作用而备受关注。然而，现有Eco-CACC研究在滚动地形上的应用仍面临挑战，且无法同时保证生态最优性与计算效率。为此，本文提出一种基于非线性最优控制的Eco-CACC控制器，具有以下特性：i) 通过空间域建模增强在滚动地形上的性能；ii) 通过全局优化所有车辆的燃油消耗提升燃油效率；iii) 通过开发基于微分动态规划的求解方法处理非线性最优控制问题，确保计算效率；iv) 通过理论证明与实验验证保证队列稳定性。对所提出Eco-CACC控制器的性能进行了评估。结果表明，该控制器在集散道路上平均节油率达37.67%，在城市主干道上约达17.30%。