Minimizing Environmental Impact of Cruise Flights using Meta-heuristic and Optimal Control Optimizations

Abstract

Aviation has a negative impact on the environment. As the number of flights is expected to increase, the total environmental impact of aviation will continue to worsen. New solutions are required to mitigate these effects. Aircraft Trajectory Optimization For Environmental Impact (TOFEI) can help reduce the impact of aircraft pollutants while also facilitating an increase in the number of flights. Whereas previous studies have shown that TOFEI can be effective in mitigating the footprint of aviation, their scope is limited. An applicable model should include wind, variable Mach number and an appropriate environmental impact metric. This paper presents the Trajectory Optimizer for Environmental Purposes (TOEP), which bridges the existing gap. The approach comprises two models, a genetic algorithm and a direct collocation model. The former finds climate-optimal trajectories using a meta-heuristic search technique, while the latter solves the problem using optimal control in CasADi. As direct collocation provides faster and more accurate results, the genetic algorithm is used to verify the direct collocation model. The algorithm uses the open aircraft performance model OpenAP. Results show that the environmental impact of flights could be reduced by as much as 6.6% when fully optimizing for this metric. The impact differs significantly between short haul flights and long haul flights, with 1.2% environmental cost reduction for the former and 2.7% for the latter. Pareto fronts are utilized to investigate the relationship between operating cost and the environmental cost.