Trajectory Optimization of Aircraft Vertical Flight Profile Based on Particle Swarm Optimization Algorithm Considering Pollutant Emission Cost

To improve flight economy and environmental friendliness, a vertical flight profile optimization method considering the cost of pollutant emissions (SO
₂
, CO, NO
_x
, CO
₂
and HC) cost is studied. Firstly, in this paper, a pollutant emission price weight, emission factor and a comprehensive cost index are proposed to establish a direct operating costs calculation model considering the pollutant emissions cost based on the ICAO baseline emission data. Secondly, based on the energy state method and the mass-point dynamics, a mass-point dynamic model of the vertical flight profile is established. Thirdly, the objective function and constraint conditions of trajectory optimization in each flight phase are derived based on the minimum principle of Pontryagin. Finally, taking B737-800 as an example, the Particle Swarm Optimization (PSO) algorithm is used to optimize the objective functions as well as fight parameters under a proper comprehensive cost index, and through simulation to realize the trajectory optimization with the optimal cost as the goal. Under the same conditions, compared the optimization result with the traditional cost index of 30, the fuel cost is reduced by 4.2%, total emissions of pollutants decreased by 4.3%, flight time increased by 7.9%, but the total cost of flight decreased by 2.1%. The simulation results show that the vertical profile trajectory optimization method proposed in this paper can effectively reduce the emissions of SO
₂
, HC, CO, NO
_x
, CO
₂
and the direct operating costs, improving the flight economic efficiency for airlines.