Trajectory optimisation has shown good potential to reduce environmental impact in aviation. However, a recurring problem is the loss in airspace capacity that fuel optimal procedures pose, usually overcome with speed, altitude or heading advisories that lead to more costly trajectories. This paper aims at the quantification in terms of fuel and time consumption of implementing suboptimal trajectories in a 4D trajectory context that use required times of arrival at specific navigation fixes. A case study is presented by simulating conflicting Airbus A320 departures from two major airports in Catalonia. It is shown how requiring an aircraft to arrive at a waypoint early or late leads to increased fuel burn. In addition, the efficiency of such methods to resolve air traffic conflicts is studied in terms of both fuel burn and resulting aircraft separations. Finally, various scenarios are studied reflecting various airline preferences with regards to cost and fuel burn, as well as different route and conflict geometries for a broader scope of study.
Vilardaga, S.; Prats, X. International Conference on Application and Theory of Automation in Command and Control Systems p. 75-84 DOI: 10.1145/2899361.2899369 Data de presentació: 2015-09 Presentació treball a congrés
Air trac predictability is paramount in the air trac sys-
tem in order to enable concepts such as Trajectory Based
Operations (TBO) and higher automation levels for self-
separation. Whereas in simulated environments 4D con ict-
free trajectory optimisation has shown good potential in
the improvement of air trac eciency, its application to
real operations has been very challenging due to the current
lack of information sharing between airspace users. Con-
sequently, such operations are still very limited in scope
and rarely attempted in dense trac situations. Better pre-
dictability of other trac future states would be an enabler
for each aircraft to y its user preferred route without de-
creasing safety in a self-separation context. But this is not
an easy task when basic aircraft parameters such as aircraft
weight, performance data or airline strategies are not avail-
able at the time of prediction. In this paper the authors pro-
pose to compensate this hindrance by continuously integrat-
ing the state of the surounding trac to improve the own-
ship's knowledge of other aircraft's dynamics. Speci cally,
conventional position (and velocity) messages, as coming
from Automatic Dependent Surveillance Broadcast (ADS-
B), are integrated at the ownship. Then, an optimisation
problem is formulated, using optimal control theory, that
minimises the error with the known states, having the pa-
rameters of study (i.e. mass) as decision variables. A sce-
nario with two departing trajectories is used to demonstrate
the e ectiveness of this parameter estimation method. In it,
the take-o mass of the potential intruder is estimated on-
board the ownship and its impact to con ict detection and
resolution is presented, demonstrating the big improvements
in predictability and safety.
Air traffic predictability is paramount in the air traffc system in order to enable concepts such as Trajectory Based Operations (TBO) and higher automation levels for self-separation. Whereas in simulated environments 4D conflict-free trajectory optimisation has shown good potential in the improvement of air traffc effciency, its application to real operations has been very challenging due to the current lack of information sharing between airspace users. Consequently, such operations are still very limited in scope and rarely attempted in dense traffic situations. Better predictability of other traffc future states would be an enabler for each aircraft to fly its user preferred route without decreasing safety in a self-separation context. But this is not an easy task when basic aircraft parameters such as aircraft weight, performance data or airline strategies are not available at the time of prediction. In this paper the authors propose to compensate this hindrance by continuously integrating the state of the surounding traffc to improve the ownship's knowledge of other aircraft's dynamics. Specifically, conventional position (and velocity) messages, as coming from Automatic Dependent Surveillance Broadcast (ADS-B), are integrated at the ownship. Then, an optimisation problem is formulated, using optimal control theory, that
minimises the error with the known states, having the parameters of study (i.e. mass) as decision variables. A scenario with two departing trajectories is used to demonstrate the e ectiveness of this parameter estimation method. In it, the take-off mass of the potential intruder is estimated on- board the ownship and its impact to conflict detection and resolution is presented, demonstrating the big improvements in predictability and safety.
WEMSgen is a stand-alone application devel-
oped within the Clean Sky FASTOP (Fast Opti-
miser for continuous descent approaches) project that
is capable to load weather data in standard GRIB
(General Regularly-distributed Information in Binary
form) files and generate piece-wise polynomial fitting
functions that can be used in a latter stage in trajectory
planning and/or optimisation algorithms. Assuming a
known lateral flight route, meteorological input data
(temperature, pressure and wind field) is fitted into
cubic B-splines as a function of the aircraft altitude
and its distance to the runway threshold. WEMSgen
can be queried in real-time by any process that needs
weather data. Thus, besides being used for trajec-
tory planning or optimisation algorithms, it also can
feed aircraft simulation or visualisation applications,
among other. WEMSgen has been successfully used
and validated in a flight simulation experiment using
the Generic Research Aircraft Cockpit Environment
(GRACE) at the National Aerospace Laboratory of
The Netherlands (NLR)
In previous research, an aircraft trajectory planning algorithm was developed aiming at
optimizing continuous descent operations with required times of arrival at given waypoints.
A non-linear optimal control problem was solved by using direct transcription methods.
In this paper, enhanced models for the same optimization framework are presented, im-
proving the accuracy of the optimized trajectories. These new models take into account
wind, realistic atmospheric conditions, curved trajectories and general improvements in the
aircraft dynamics model. Preliminary results are shown in a hypothetical scenario where
trajectories are optimized from cruise altitude to the runway with different required times
of arrival at the threshold. The effects of wind and non-standard atmospheres can be easily
In an effort to improve the effciency of air traffic operations, whilst reducing the envi-
ronmental impact on aviation and increase capacity, 4D trajectory optimisation has shown
good potential. In previous research the authors have described a framework where com-
plex departure routes can be optimised, producing con
ict free fuel optimal trajectories.
The research in this paper extends this concept to account for prediction uncertainty of
future states of intruding traffic. It is proposed to continuously monitor the surounding
traffic and recompute the ownship trajectory whenever a deviation from nominal traffic
behavior arises. The effectiveness of the conformance monitoring function is evalutated in
a scenario with two aircraft
ying standard departing procedures from Barcelona and Reus
This paper proposes to create a taxonomy of separation conflicts between Unmanned Aerial Systems (UAS) and intruding aircrafts to facilitate its insertion in non- segregated airspace. The classification is created according to the relative speeds, angular geometry, initial intent, etc. A catalog of separation maneuvers that best fit each scenario is introduced and evaluated through a real-time simulation environment. This advisory mechanism will benefit both the UAS pilot and the ATCo in order to negotiate the best suited separation maneuver. Eventually, the same strategy can be employed as an autonomous separation system on-board a UAS that suffers a lost-link contingency, alleviating its negative impact in the airspace.
ATACCS Conference - Boeing Best PhD Paper Award. SESAR HALA! network (2013-05-31 )
4D trajectory optimisation has showed good potential to reduce environmental impact in aviation. However, a
recurrent problematic is the loss in air traffic capacity that these pose, usually overcome with speed and time advisories. This paper aims at the quantification in terms of fuel consumption of implementing suboptimal trajectories to preserve capacity. Via an own developed optimisation framework, we deliver results on how imposing a nonoptimal RTA to a trajectory increases the fuel burned. We show how advancing a metering fix in an example departure trajectory translates to an increase of up 15Kg of
fuel burned. Similarly, postponing it 50s, will burn around 23Kg more. Also, imposing a level off phase (due to incoming traffic) will typically consume around 25Kg more. Different scenarios
'In the conventional aircraft approach the aircraft receives clearance from Air Traffic Control to descent from the bottom level of the holding stack to a given altitude where it would fly level until intercepting the 3 degree glidepath to the runway. In this flight level segment the aircraft requires additional engine power to maintain constant speed, resulting in an increase of fuel consumption and noise.
A new approach procedure called Continuous Descent Approach (CDA) has been developed and is becoming widespread. In CDA procedures the aircraft stays higher for longer and then descends continuously, avoiding level segments, to the intercept point of the 3 degree glidepath. The CDA approaches reduce fuel consumption, CO2 and NOx emissions as well as noise levels.
To take full advantage of CDA approaches, the continuous descent paths can be optimized to decrease even more the fuel consumption and noise and pollutant emissions. This proposal addresses an onboard fast optimiser for continuous descent approaches which calculates descent profiles minimizing the use of engine thrust and speed brakes while meeting ATC time requirements and maintaining airport landing capacity.
To ensure a successful development of the fast optimiser, the Fastop proposal has been written by a consortium with remarkable parties skills that cover all the mathematical, programming and management needs required by the topic.'
'Recent dramatic events such as the earthquakes in Haiti and L’Aquila or the flooding in Pakistan have shown that local civil authorities and emergency services have difficulties with adequately managing crises. The result is that these crises lead to major disruption of the whole local society. The goal of ICARUS is to decrease the total cost (both in human lives and in €) of a major crisis. In order to realise this goal, the ICARUS project proposes to equip first responders with a comprehensive and integrated set of unmanned search and rescue tools, to increase the situational awareness of human crisis managers and to assist search and rescue teams for dealing with the difficult and dangerous, but life-saving task of finding human survivors.
As every crisis is different, it is impossible to provide one solution which fits all needs. Therefore, the ICARUS project will concentrate on developing components or building blocks that can be directly used by the crisis managers when arriving on the field. The ICARUS tools consist of assistive unmanned air, ground and sea vehicles, equipped with human detection sensors. The ICARUS unmanned vehicles are intended as the first explorers of the area, as well as in-situ supporters to act as safeguards to human personnel. The unmanned vehicles collaborate as a coordinated team, communicating via ad hoc cognitive radio networking. To ensure optimal human-robot collaboration, these ICARUS tools are seamlessly integrated into the C4I equipment of the human crisis managers and a set of training and support tools is provided to the human crisis to learn to use the ICARUS system.
Furthermore, the project aims to provide an integrated proof-of-concept solution, to be evaluated by a board of expert end-users that can verify that operational needs are addressed.'