Multi-objective optimization of flight trajectories for mitigating the climate impact from aviation
| Reference No. | 20210018 |
|---|---|
| Type/Category | Grant for General Research-Short-term Joint Research |
| Title of Research Project | Multi-objective optimization of flight trajectories for mitigating the climate impact from aviation |
| Principal Investigator | Hiroshi Yamashita（Deutsches Zentrum fur Luft- und Raumfahrt e.V. (DLR), Institut fur Physik der Atmosphare・Postdoctoral researcher） |
| Research Period |
December 15,2021. ～
December 16,2021. |
| Keyword(s) of Research Fields | Multi-objective optimization, Differential topology, Structural stability, Topological analysis in visualization |
| Abstract for Research Report |
Climate impact of aviation emissions is a topic studied world-wide because of its importance for a sustainable society, and thus aviation industry is required to reduce the impact. The aviation climate impact consists of carbon dioxide (CO2) emissions and of non-CO2 effects, which consist of concentration changes of ozone, methane, water vapor, persistent linear contrails and contrail-induced cirrus clouds. They have different timescales of the impacts. Thus, the impact of both CO2 and non-CO2 effects must be considered to evaluate the aviation climate impact. The current aircraft routing strategy in the airline industry tends to optimize the financial cost of operation with little consideration on the environmental sustainability. However, if additional costs (e.g., environmental taxes) for aviation climate impact of CO2 and non-CO2 effects are included in the operating cost, another aircraft routing strategy is needed; that is, both the operating cost and the climate impact of aviation emissions need to be considered for the sustainable development of aviation. Generally, a trade-off exists between the operating cost and the climate impact. To support airlines in finding a practical solution to the trade-off, eco-efficient flight trajectories are investigated by using the chemistry?climate model EMAC. The EMAC model is a numerical chemistry and climate simulation system which includes submodels describing tropospheric and middle atmosphere processes and their interaction with oceans, land, and influences coming from anthropogenic emissions. Although a multi-objective optimization of flight trajectories is solved and a set of Pareto-optimal solutions are found in EMAC model simulations, the following decision-making process takes time, because the dimensionality of Pareto fronts becomes high in such real-world optimization problems. An efficient method needs to be developed to explore a geometry of the Pareto fronts among multiple objectives, understand it, and select a compromise solution among the set of Pareto-optimal solutions according to user preferences. The method could establish an eco-efficient routing strategy. In this collaborative research, we attempt to use the Reeb graph to explore a topological structure of Pareto fronts. This method enables one to detect knee points with a visualization of the geometry of the Pareto fronts. We examine how the Reeb graph captures the knee points and the geometry of the Pareto fronts. We also examine an application of the Reeb space algorithm that works for arbitrary dimensional domains to our optimization problem. This research deals with the real-world and concrete optimization problem on aviation and climate change on the basis of numerical simulations. However, the problem has the essential core of the issue; that is, the analysis of high-dimensional fields. We exchange ideas among researchers who work on multi-objective optimization, differential topology and meteorology, and develop an optimization method for aircraft routing towards sustainable development of aviation industry. |
| Organizing Committee Members (Workshop) Participants (Short-term Joint Usage) |
Hiroshi Yamashita（Deutsches Zentrum fur Luft- und Raumfahrt e.V. (DLR), Institut fur Physik der Atmosphare・Postdoctoral researcher） Bastian Kern（Deutsches Zentrum fur Luft- und Raumfahrt e.V. (DLR), Institut fur Physik der Atmosphare・Postdoctoral researcher） Naoki Hamada （KLab inc. ・Research Engineer） Daisuke Sakurai（Pan-Omics Data-Driven Innovation Research Center, Research Institute for Information Technology, Kyushu University・Associate Professor） |