Multiple-phase trajectory optimization for formation flight in civil aviation
Multiple-phase trajectory optimization for formation flight in civil aviation
复制标题
民航编队飞行多阶段轨迹优化
作者：
S. Hartjes;Marco E. G. Hellenberg Hubar;H. Visser
本文开发了一种工具，用于优化寻求加入编队的多架客机的轨迹，以最大限度地减少总体燃油消耗或直接运营成本。所开发的优化框架依赖于最优控制理论来解决与飞行编队装配相关的多阶段优化问题。采用降阶点质量公式来模拟扩展飞行编队内的飞机动力学，以及连接飞行编队与始发机场和目的地机场的单飞段。当编队时，应用折扣率来模拟尾随飞机的诱导阻力的减少。利用所开发的工具，对跨越北大西洋的两架飞机编队飞行的组装进行了个案研究。给出的结果说明了编队轨迹的综合，并展示了减少燃料和运营成本的潜力。各种数值实验的结果表明，与单独飞行相比，即使保持原来的飞行时间，编队飞行也可以显著降低燃油消耗。此外，结果清楚地揭示了当一架试图加入编队的飞机遭遇起飞延误时，飞行编队任务的性能和特点--特别是会合点和分割点的位置--是如何受到影响的。
In this paper a tool is developed that optimizes the trajectories of multiple airliners that seek to join in formation to minimize overall fuel consumption or direct operating cost. The developed optimization framework relies on optimal control theory to solve the multiple-phase optimization problem associated to flight formation assembly. A reduced-order point-mass formulation is employed for modelling of the aircraft dynamics within an extended flight formation, and of the solo flight legs that connect the flight formation to the origin and destination airports. When in formation, a discount factor is applied to simulate a reduction in the induced drag of the trailing aircraft. Using the developed tool a case study has been conducted pertaining to the assembly of two-aircraft formation flights across the North-Atlantic. Results are presented to illustrate the synthesis of the formation trajectories and to demonstrate the potential for reducing fuel and operating cost. The results of the various numerical experiments show that formation flight can lead to significant reductions in fuel consumption compared to flying solo, even when the original trip times are maintained. Additionally, the results clearly reveal how the performance and the characteristics of the flight formation mission—notably the location of rendezvous and splitting points—are affected when one aircraft seeking to join the formation suffers a departure delay.