The purpose of the project was the overview of the state of the art of collocation optimisation techniques, to make a full definition of the optimisation problem applied to an aircraft dynamics and develop a software package based on optimisation collocation techniques to find the optimum trajectory of an aircraft.
One of the integrated technology demonstrators around which the CLEAN SKY Joint technology initiative (JTI) was articulated is the Systems for green operations (SGO) which focuses on all-electrical aircraft equipment and systems architectures, thermal management, capabilities for 'green' trajectories and mission and improved ground operations to give any aircraft the capability to fully exploit the benefits of SES.
In particular, the SGO aimed at defining new approaches for the management of trajectory and mission for an overall optimisation of the aircraft and systems by implementing the following two concepts:
- Green trajectories, based on more precise, reliable and predictable three-dimensional (3D) flight path, optimised for minimum noise impact and low emission, including agile trajectory management, in response to meteorological hazard.
- A green mission from start to finish, with management of new climb, cruise and descent profiles, based on new aircraft performances database which includes noise parameter and allows multi-criteria optimisation (noise, emissions, fuel, time), including management of weather conditions which could negatively impact the aircraft optimum route and results in additional fuel consumption.
The POTRA project has been devoted to analyse and develop the following points:
- overview of the state of the art of collocation optimisation techniques;
- definition of the theoretical problem to solve;
- specification of the numerical optimisation techniques applicable to the problem;
- developing of a numerical optimisation software package;
- define the validation methodology and perform numerical simulations.
As a result of this project a tool has been developed with the following functionalities:
- 4D trajectories (e.g. emulate CCB, FRA, CDO, point to point);
- considered trajectory constraints;
- aircraft dynamics and operational weights;
- fly over fixes with altitude bands (user defined, SIDs and STARs);
- altitude bands at each trajectory segment between fixes;
- direct operations cost;
- fuel consumption;
- flight duration (CI);
- noise charges (noise stations).