S. Hartjes

Optimisation of RNAV noise and emission abatement standard instrument departures

In an effort to reduce the negative impact of civil aviation on the human environment, trajectory optimisation techniques have been used to minimise the single event impact of noise and gaseous emissions of departures on communities in the vicinity of airports. For this purpose, the earlier developed trajectory optimisation tool NOISHHH has been adapted to design departure trajectories optimised for environmental criteria, based on area navigation. The new version of NOISHHH combines a noise model, an emissions inventory model, a geographic information system and a dynamic trajectory optimisation algorithm to generate flight paths with minimised environmental impact. Operational constraints have been introduced to ensure that the resulting flight paths are fully compliant with the guidelines and regulations that apply to the design of standard instrument departures and the use of area navigation. To illustrate the capabilities of the new version of NOISHHH, two numerical examples are presented, which are both redesigns of standard instrument departures currently in use at Amsterdam Airport Schiphol.

An improved MOEA/D algorithm for bi-objective optimization problems with complex Pareto fronts and its application to structural optimization

The multi-objective evolutionary algorithm based on decomposition (MOEA/D) has been recognized as a promising method for solving multi-objective optimization problems (MOPs), receiving a lot of attention from researchers in recent years. However, its performance in handling MOPs with complicated Pareto fronts (PFs) is still limited, especially for real-world applications whose PFs are often complex featuring, e.g., a long tail or a sharp peak. To deal with this problem, an improved MOEA/D (named iMOEA/D) that mainly focuses on bi-objective optimization problems (BOPs) is therefore proposed in this paper. To demonstrate the capabilities of iMOEA/D, it is applied to design optimization problems of truss structures. In iMOEA/D, the set of the weight vectors defined in MOEA/D is numbered and divided into two subsets: one set with odd-weight vectors and the other with even-weight vectors. Then, a two-phase search strategy based on the MOEA/D framework is proposed to optimize their corresponding populations. Furthermore, in order to enhance the total performance of iMOEA/D, some recent developments for MOEA/D, including an adaptive replacement strategy and a stopping criterion, are also incorporated. The reliability, efficiency and applicability of iMOEA/D are investigated through seven existing benchmark test functions with complex PFs and three optimal design problems of truss structures. The obtained results reveal that iMOEA/D generally outperforms MOEA/D and NSGA-II in both benchmark test functions and real-world applications.

Economic and environmental optimization of flight trajectories connecting a city-pair

This paper describes the development of a multi-phase/multi-criteria trajectory optimization framework that has been conceived to support the synthesis of green mission profiles that will allow aircraft to fly optimum flight paths with the lowest possible noise and emissions. The proposed multi-phase/multi-criteria framework is not only suitable to formulate trajectory optimization problems in which noise, emissions, or global warming effects can be simultaneously considered, but also provides the possibility to implement air traffic management constraints that apply to certain flight stages. A case study involving a trip from Amsterdam Airport Schiphol to Munich Franz Josef Strauss International Airport is presented to illustrate the synthesis of green trajectories and to demonstrate the potential for improving the environmental footprint. The optimization results bear out that optimizing with respect to noise can be very rewarding in terms of reducing the local noise impact, without significantly affecting the overall flight-economic performance.

Development of a Multi-Event Trajectory Optimization Tool for Noise-Optimized Approach Route Design

This paper presents preliminary results from an ongoing research effort towards the development of a multi-event trajectory optimization methodology that allows to synthesize RNAV approach routes that minimize a cumulative measure of noise, taking into account the total noise effect aggregated for all inbound flight movements taking place within an operational year. This new development is an extension of a tool called NOISHHH which was developed earlier for the synthesis of single-event noise abatement RNAV trajectories into and out of airports. Although the presented numerical examples pertain to a specific airport in the Netherlands, viz. Rotterdam the Hague airport, this study focuses on the development of a generic methodology that can be applied to any given airport. Initial application of the adapted optimization framework to the design of noise abatement RNAV approach routes at Rotterdam The Hague airport reveals a significant potential for reducing the number of people highly annoyed due to annual noise exposure relative to the existing situation.

Optimization of RNAV Noise and Emission Abatement Departure Procedures

In an effort to reduce the negative aspects of civil aviation on the human environment, trajectory optimization techniques have been used to reduce the single event impact of noise and gaseous pollutants of departures on communities in the vicinity of airports. For this purpose, the trajectory optimization tool NOISHHH has been adapted to design departure procedures based on Area Navigation. The new version of NOISHHH combines a noise model, an emission inventory model, a Geographic Information System and a dynamic trajectory optimization algorithm to generate flight paths with minimized noise impact and emissions. By introducing a variety of operational constraints, the resulting flight paths developed with the adapted version of NOISHHH fully comply with the regulations and guidelines applying to the design of Standard Instrument Departures and the use of Area Navigation. To illustrate the possibilities of the new version a numerical example is presented. This example is a redesign of an existing Standard Instrument Departure currently in use at Amsterdam Airport Schiphol.

Optimization of Area Navigation Arrival Routes for Cumulative Noise Exposure

This paper presents a study aimed at the development of an optimization methodology for multi-event aircraft trajectories. The proposed methodology is an extension of the NOISHHH tool originally developed for the optimization of single-event trajectories. The new optimization framework has been developed to synthesize multi-event area navigation trajectories that minimize the community noise impact in near-airport communities due to the aggregated noise impact on near-airport communities of all inbound and outbound flights on a representative day. The methodology has been applied to nightly inbound flights at a large international airport, revealing a significant improvement of the community noise impact in terms of the number of people highly annoyed due to aircraft noise.

Multiple-Phase Trajectory Optimization for Formation Flight in Civil Aviation

In this paper a tool is developed that optimizes the trajectories of multiple airliners that seek to join in formation to minimize overall fuel consumption or Direct Operating Cost (DOC). The developed optimization framework relies on optimal control theory to solve the multiple-phase optimization problem associated to flight formation assembly. A reduced-order point-mass formulation is employed for modelling of the aircraft dynamics within an extended flight formation, and of the solo flight legs that connect the flight formation to the origin and destination airports. When in formation, a discount factor is applied to simulate a reduction in the induced drag of the trailing aircraft. Using the developed tool a case study has been conducted pertaining to the assembly of two-aircraft formation flights across the North-Atlantic. Results are presented to illustrate the synthesis of the formation trajectories and to demonstrate the potential for reducing fuel and operating cost. The results of the various numerical experiments show that formation flight can lead to significant reductions in fuel consumption compared to flying solo, even when the original trip times are maintained. Also, the results clearly reveal how the performance and the characteristics of the flight formation mission - notably the location of rendezvous and splitting points - are affected when one aircraft seeking to join the formation suffers a departure delay.