4DT generator and guidance system

This thesis describes a 4D Trajectories Generator and Guidance system. 4D trajectory is a concept that will improve the capacity, efficiency and safety of airspace. First a 4D trajectories synthetizer design is proposed. A flight plan composed by a set of waypoints, aircraft dynamics model and a set of limits and constraints are assembled into an optimal control problem. Optimal solution is found by making use of an optimal control solver which uses pseudo spectral parametrization together with a generic nonlinear programming solver. A 4D Trajectories generator is implemented as a stand-alone application and combined with a graphic user interface to give rise to 4D Trajectories Research Software (4DT RS) capable to generate, compare and test optimal trajectories. A basic Tracking & Guidance system with proportional navigation concept is developed. The system is implemented as a complementary module for the 4D trajectories research software. Simulation tests have been carried out to demonstrate the functionalities and capabilities of the 4DT RS software and guidance system. Tests cases are based on fuel and time optimization on a high-traffic commercial route. A standard departure procedure is optimized in order to reduce the noise perceived by village’s population situated near airport. The tracking & guidance module is tested with a commercial flight simulator for demonstrating the performance of the optimal trajectories generated by the 4DT RS software

Short-term air traffic flow and capacity management measures in multi-airport systems.

Dynamic Demand and Capacity Balancing (dDCB) focuses on reducing the existent gap between the Air Traffic Flow and Capacity Management (ATFCM) and the Air Traffic Control (ATC) activities by introducing a more dynamic management of the airspace resources. This dynamism could be achieved by the application of Short-Term ATFCM Measures (STAM) that consists of detecting potential hotspots, identifying the flights producing the complexity, and applying minor changes to selected flights. This thesis presents a research about the application of STAM in a Multi-Airport System (MAS). Firstly, it is proposed an Operational Concept (OpsCon) designed to apply those STAMs that suggest changes in the take-off time of selected flights (temporal displacements in the planned trajectory). The operational concept is tested by real-time simulations (including the human- in-the-loop) with the objective of evaluating the performance of the ground ATCOs while dealing with most of the uncertainties produced before take-off. Subsequently, it is proposed a methodology that characterizes and evaluates the performance of the aircraft operation in a complex systemized TMA based on the study of its standard routes and their actual traffic in order to reduce the uncertainties after take-off. The process is composed of two main components. The first component identifies recurrent deviation patterns by comparing the Spatio-Temporal (S-T) differences between the actual and planned trajectories. The second component identifies and characterizes concurrence events based on the analysis of the standard routes and the along-track deviation derived from the first component with the objective to analyse the causes that produce recurrent patterns in the terminal airspace. The developed framework is applied to a study case of a representative MAS. The quantitative effectiveness of the framework is derived by simulations using historical traffic data samples of the London TMA.PhD in Aerospac

Design of a FMS to support four-dimensional trajectories

The increase of air traffic rates registered in the recent years and the forecast for the next twenty years, has encouraged the necessity of developing new alternatives to manage the airspace. For this reason, several European and American organizations have been studying the idea of introducing new Air Traffic Management (ATM) systems based on four-dimensional trajectories. The four-dimensional trajectory management consists in establishing far in advance a time-based sequence for all aircraft converging to a specific point. The main idea is providing each aircraft with a time constraint to get a specific merging point. As a result, it is allowed to the aircraft to perform autonomous flight in order to achieve this merging point in the required time. In case the aircraft is not able to arrive to the merging point at the required time, it is assigned a new time of arrival; this means the aircraft has to perform Holding Patterns (HP) procedures, which is traduced to more fuel consumed, more emissions produced and several issues related to airlines and airport delays. A new generation of avionics systems related to navigation and flight management is emerging in order to support precision trajectories based on waypoints composed by latitude, longitude, altitude and a fourth dimension represented by the time. The purpose of this project is to design, simulate and test the functions of a Flight Management System (FMS) in order to follow automatically four-dimensional trajectories. This is achieved by controlling the aircraft airspeed, altitude, heading and vertical speed in order to arrive to the merging point in the specified time. The system receives data from the aircraft and computes new control parameters based on mathematical equations and prediction trajectories algorithms. Additional features has been added to the FMS-4D, such as the capability of predicting the arrival time taking into account previous flight parameters and speed/altitude constrains. Finally, a testing phase is performed using a flight simulator in order to obtain the performance and results of the designed system

Design of a flight management system to support four-dimensional trajectories

This paper presents the design and simulation of the functions of a flight Management System (FMS) in order to follow four-dimensional trajectories automatically. This is achieved by controlling the aircraft’s airspeed, altitude, heading and vertical speed in order to arrive to the merging point in a specified time. The system receives data from the aircraft and computes new control parameters based on mathematical equations and algorithms of prediction trajectories. Additional features have been added to the FMS-4D, such as the capability of predicting the arrival time taking into account previous flight parameters and speed/altitude constrains. Finally, a testing phase was carried out using a flight simulator in order to obtain the performance and results of the designed system.Peer ReviewedPostprint (author's final draft

A machine learning approach to air traffic interdependency modelling and its application to trajectory prediction

Air Traffic Management is evolving towards a Trajectory-Based Operations paradigm. Trajectory prediction will hold a key role supporting its deployment, but it is limited by a lack of understanding of air traffic associated uncertainties, specifically contextual factors. Trajectory predictors are usually based on modelling aircraft dynamics based on intrinsic aircraft features. These aircraft operate within a known air route structure and under given meteorological conditions. However, actual aircraft trajectories are modified by the air traffic control depending on potential conflicts with other traffics. This paper introduces surrounding air traffic as a feature for ground-based trajectory prediction. The introduction of air traffic as a contextual factor is addressed by identifying aircraft which are likely to lose the horizontal separation. For doing so, this paper develops a probabilistic horizontal interdependency measure between aircraft supported by machine learning algorithms, addressing time separations at crossing points. Then, vertical profiles of flight trajectories are characterised depending on this factor and other intrinsic features. The paper has focused on the descent phase of the trajectories, using datasets corresponding to an en-route Spanish airspace volume. The proposed interdependency measure demonstrates to identify in advance conflicting situations between pairs of aircraft for this use case. This is validated by identifying associated air traffic control actions upon them and their impact on the vertical profile of the trajectories. Finally, a trajectory predictor for the vertical profile of the trajectory is developed, considering the interdependency measure and other operational factors. The paper concludes that the air traffic can be included as a factor for the trajectory prediction, impacting on the location of the top of descent for the specific case which has been studied

Design of a FMS to support four-dimensional trajectories

The increase of air traffic rates registered in the recent years and the forecast for the next twenty years, has encouraged the necessity of developing new alternatives to manage the airspace. For this reason, several European and American organizations have been studying the idea of introducing new Air Traffic Management (ATM) systems based on four-dimensional trajectories. The four-dimensional trajectory management consists in establishing far in advance a time-based sequence for all aircraft converging to a specific point. The main idea is providing each aircraft with a time constraint to get a specific merging point. As a result, it is allowed to the aircraft to perform autonomous flight in order to achieve this merging point in the required time. In case the aircraft is not able to arrive to the merging point at the required time, it is assigned a new time of arrival; this means the aircraft has to perform Holding Patterns (HP) procedures, which is traduced to more fuel consumed, more emissions produced and several issues related to airlines and airport delays. A new generation of avionics systems related to navigation and flight management is emerging in order to support precision trajectories based on waypoints composed by latitude, longitude, altitude and a fourth dimension represented by the time. The purpose of this project is to design, simulate and test the functions of a Flight Management System (FMS) in order to follow automatically four-dimensional trajectories. This is achieved by controlling the aircraft airspeed, altitude, heading and vertical speed in order to arrive to the merging point in the specified time. The system receives data from the aircraft and computes new control parameters based on mathematical equations and prediction trajectories algorithms. Additional features has been added to the FMS-4D, such as the capability of predicting the arrival time taking into account previous flight parameters and speed/altitude constrains. Finally, a testing phase is performed using a flight simulator in order to obtain the performance and results of the designed system

Design of a flight management system to support four-dimensional trajectories

This paper presents the design and simulation of the functions of a flight Management System (FMS) in order to follow four-dimensional trajectories automatically. This is achieved by controlling the aircraft’s airspeed, altitude, heading and vertical speed in order to arrive to the merging point in a specified time. The system receives data from the aircraft and computes new control parameters based on mathematical equations and algorithms of prediction trajectories. Additional features have been added to the FMS-4D, such as the capability of predicting the arrival time taking into account previous flight parameters and speed/altitude constrains. Finally, a testing phase was carried out using a flight simulator in order to obtain the performance and results of the designed system.Peer Reviewe