Nils Ahrenhold

Mr. Nils Ahrenhold

Air Traffic Management Simulation, Institute of Flight Guidance, Braunschweig, Lower Saxony, Germany
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Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 October 2021 in Infrastructures
Verified
Journal Article
Open access
PDF file
NANils Ahrenhold
Nils Ahrenhold
OPOliver Pohling
Oliver Pohling
Sebastian Schier-MorgenthalSebastian Schier-Morgenthal
Sebastian Schier-Morgenthal
The extension of the current urban transportation system utilising the third dimension by air taxi (AT) operations represents a potential solution for the congestion of metropolitan areas. A major asset for AT operations is the connection to existing airports enabling the access to multiple other transportation systems. This paper develops an analytical model for AT operations and their capacity impact on airports, exemplary for Hamburg airport. The model is developed, based on the results of a fast time simulation (FTS) considering multiple aspects, such as vehicle configuration and touchdown and lift-off areas (TLOF). Collectively, three integration methods were analysed, each of them impacting the conventional air traffic differently. The results show that an integration using the runway-system is not possible with five ATs per hour. Further methods allow an integration of up to 20 air taxis per hour. Additionally, an energy consumption analysis of the ATs is conducted. Finally, proposals are given for integrating ATs at an airport and further strategies to extend the analytical model. Through this work, a model to calculate and predict an AT’s influence on the airside capacity of an airport is designed. This is an important step for the practical implementation of AT operations at airports.

26 April 2023 in Aerospace
Verified
Journal Article
Open access
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NANils Ahrenhold
Nils Ahrenhold
IGIngrid Gerdes
Ingrid Gerdes
TMThorsten Mühlhausen
Thorsten Mühlhausen
ATAnnette Temme
Annette Temme
Dynamic sectorization is a powerful possibility to balance the controller workload with respect to traffic flows changing over time. A multi-objective optimization system analyzes the traffic flow over time and determines suitable time-dependent sectorizations. Our dynamic sectorization system is integrated into a radar display as part of a working environment for air traffic controllers. A use case defining climate-sensitive areas leads to changes in traffic flows. When using the system, three controllers are assessed in two scenarios: the developed controller assistance system and the work in a dynamic airspace sectorization environment. We performed a concept validation in which we evaluated how controllers cope with sectors adapting to the traffic flow. The solution was rated as highly applicable by the involved controllers. The trials revealed the necessity to adapt the current procedures and define new aspects more precisely. In this paper, we present the developed environment and the theoretical background as well as the traffic scenarios. Furthermore, we describe the integration in an Air Traffic Management (ATM) environment and the questionnaires developed to assess the functionality of the dynamic sectorization approach. Finally, we present a proposal to enhance controller guidelines in order to cope with situations emerging from dynamic sectorizations, including naming conventions and phraseology.

5 June 2023 in Aerospace
Verified
Journal Article
Open access
PDF file
NANils Ahrenhold
Nils Ahrenhold
Hartmut HelmkeHartmut Helmke
Hartmut Helmke
TMThorsten Mühlhausen
Thorsten Mühlhausen
Oliver OhneiserOliver Ohneiser
Oliver Ohneiser
MKMatthias Kleinert
Matthias Kleinert
JGJuan Pablo Zuluaga Gomez
Juan Pablo Zuluaga Gomez
Automatic speech recognition and understanding (ASRU) for air traffic control (ATC) has been investigated in different ATC environments and applications. The objective of this study was to quantify the effect of ASRU support for air traffic controllers (ATCos) radar label maintenance in terms of safety and human performance. Therefore, an implemented ASRU system was validated within a human-in-the-loop environment by ATCos in different traffic-density scenarios. In the baseline condition, ATCos performed radar label maintenance by entering verbally instructed ATC commands with a mouse and keyboard. In the proposed solution, ATCos were supported by ASRU, which achieved a command recognition rate of 92.5% with a command error rate of 2.4%. ASRU support reduced the number of wrong or missing inputs from ATCos into the radar label by a factor of two, which contemporaneously improved their situational awareness. Furthermore, ATCos where able to perform more successful secondary tasks when using ASRU support, indicating a greater capacity to handle unexpected events. The results from NASA TLX showed that the perceived workload decreased with a statistical significance of 4.3% across all scenarios. In conclusion, this study provides evidence that using ASRU for radar label maintenance can significantly reduce workload and improve flight safety.

11 March 2023 in Aerospace
Verified
Journal Article
Open access
PDF file
NANils Ahrenhold
Nils Ahrenhold
ISIzabela Stasicka
Izabela Stasicka
RARabeb Abdellaoui
Rabeb Abdellaoui
TMThorsten Mühlhausen
Thorsten Mühlhausen
MTMarco-Michael Temme
Marco-Michael Temme
Growing political pressure and widespread social concerns about climate change are triggering a paradigm shift in the aviation sector. Projects with the target of reducing aviation’s CO2 emissions and their impact on climate change are being launched to improve currently used procedures. In this paper, a new coordination process between aircraft flight management systems (FMSs) and an arrival manager (AMAN) was investigated to enable fuel-efficient and more sustainable approaches. This coordination posed two major challenges. Firstly, current capacity-centred AMANs’ planning processes are not optimised towards fuel-efficient trajectories. To investigate the benefit of negotiated trajectories with fixed target times for waypoints and thresholds, the terminal manoeuvring area was redesigned for an independent parallel runway system. Secondly, the FMS-AMAN negotiation process plan the trajectories based on time, whereas air traffic controllers guide traffic based on distance. Three tactical assisting tools were implemented in an air traffic controller’s working position to enable a smooth transition from distance-based to time-based coordination and guidance. The whole concept was implemented and tested in real-time human-in-the-loop studies at DLR’s Air Traffic Validation Center. Results showed that the new airspace design and concept was feasible, and a reduction in flown distance was measured.

1 October 2024 in Journal of Air Transportation
Verified
Journal Article
Closed access
Hartmut HelmkeHartmut Helmke
Hartmut Helmke
MKMatthias Kleinert
Matthias Kleinert
Oliver OhneiserOliver Ohneiser
Oliver Ohneiser
NANils Ahrenhold
Nils Ahrenhold
LKLucas Klamert
Lucas Klamert
PMPetr Motlicek
Petr Motlicek
Air traffic controllers (ATCos) quantified the benefits of automatic speech recognition and understanding (ASRU) on workload and flight safety. As a baseline procedure, ATCos manually enter all verbal clearances into the aircraft radar labels by mouse. In our proposed solution, ATCos are supported by ASRU, which is capable of delivering the required radar label updates automatically. ATCos need to visually review the ASRU-based label updates and only have to make corrections in case of misinterpretations. Overall, the amount of time required for manually inserting clearances, i.e., by selecting the correct input in the radar labels, was reduced from 12,700 s during 14 hours of simulation time down to 405 s when ATCos were supported by ASRU. Considering the additional time of mental workload for verifying ASRU output, there is still a saving of more than one-third of the time for radar label updates. This paper also considers safety aspects, i.e., how often incorrect inputs into aircraft radar labels occur with ASRU. The number of wrong or missing inputs is less than without ASRU support. This paper advances the use case that ASRU could potentially improve safety and efficiency for ATCo operations for arrivals.

5 April 2022
Verified
Conference Paper
Closed access
GSGunnar Schwoch
Gunnar Schwoch
NANils Ahrenhold
Nils Ahrenhold
TMThorsten Muhlhausen
Thorsten Muhlhausen
The non-segregated integration of remotely piloted aircraft systems (RPAS) into the existing air traffic management structures, particularly at and around airports, is still an open task. The INVIRCAT project aims at developing a concept of operations for RPAS in the airport vicinity under instrument flight rules. Furthermore, the project assesses this concept through real-time simulations. One part of the simulation activities focused on the arrival of instrument flights at Düsseldorf international airport (EDDL). The simulation assessed the impact of the integration of RPAS on air traffic control, and the adequacy of procedures and phraseology for data link loss introduced by the developed concept. For this purpose, external air traffic controllers have been trained at the controller working positions and then been confronted with arriving RPAS. In case of data link loss, the RPAS were programmed to enter certain new determined contingency loiter areas separated from the regular arrival streams. After regaining the data link, the RPAS remained in the contingency loiter area until instructed by air traffic control otherwise. Voice communication between remote pilot and air traffic controller remained available through all simulation runs. Both remote pilot and air traffic controller were provided with suggested phraseology for the case of data link loss. During the simulation runs, the controllers were asked to indicate their perceived workload. After each simulation run, participants have been provided with a questionnaire, asking for their feedback on the applied and available procedures as well as the adequacy of the used phraseology. The workload was shown to be not affected negatively by the integration of RPAS. The event of a data link loss only temporarily and slightly increased the workload and quickly returned to lower values afterwards. Both the introduced procedures and the introduced phraseology were welcomed and rated to be adequate and useful for the purpose of safe integration of RPAS into terminal manoeuvring areas and airports under instrument flight rules.