Aircraft Trajectory Optimisation

Innovative technologies for high lift devices offer the possibility of flying new alternative approach or landing procedures in civil air transportation. Besides airport capacity, noise reduction is one of the most important goals of future air traffic. Within the Lufo III “Verbundprojekt IHK-HICON: Untersuchung neuer Hochauftriebssysteme” a systematic approach has been developed for objective evaluation of A/C performance regarding noise emission, fuel consumption, approach time and handling qualities of the piloted aircraft as well as for designing new optimal trajectories regarding all relevant evaluation criteria in order to exploit the benefit of high lift devices.

For this the analysis and optimisation environment MOPS (Multi Objective Parameter Synthesis) has been applied as methodological platform.Proprietary trajectory generation modules and evaluation models, e.g. for noise propagation, have been integrated in the MOPS environment. Experimental noise criteria have been developed in order to adequately express air traffic noise spread on ground.

The utility of the developed evaluation models and tools has been demonstrated by designing optimal landing trajectories allowing steeper glide slope angles. In addition, a robust glide slope controller was developed capable to fly the optimal trajectories automatically.

Projects

These activities can now be continued within CleanSky Systems for Green Operations ITD (launched in October 2008) where a ‘transversal optimisation framework’ for mission and trajectories is envisaged. Our contribution to this tool will be an efficient trajectory generator for realistic flight paths. Moreover multi-objective optimisation and decision strategies and concepts will be investigated with respect to trajectory optimisation for green operations.

As well current investigations in the context of navigation and guidance of Unmanned Aerial Vehicles (UAV) also involve the usage of trajectory optimisation methods. The main focus in this field is the computation of fuel- and time-optimal flights as well as optimal interception/avoidance.

Autor: Hans-Dieter Joos, Reiko Müller, DLR RM