(searched for: doi:10.2514/atcq.23.4.325)
The Aeronautical Journal, Volume 126, pp 345-364; https://doi.org/10.1017/aer.2021.67
Considering the shortcomings of current methods for real-time resolution of two-aircraft flight conflicts, a geometric optimal conflict resolution and recovery method based on the velocity obstacle method for two aircraft and a cooperative conflict resolution method for multiple aircraft are proposed. The conflict type was determined according to the relative position and velocity of the aircraft, and a corresponding conflict mitigation strategy was selected. A resolution manoeuvre and a recovery manoeuvre were performed. On the basis of a two-aircraft conflict resolution model, a multi-aircraft cooperative conflict resolution game was constructed to identify an optimal solution for maximising group welfare. The solution and recovery method is simple and effective, and no new flight conflicts are introduced during track recovery. For multi-aircraft conflict resolution, an equilibrium point that maximises the welfare function of the group was identified, and thus, an optimal strategy for multi-aircraft conflict resolution was obtained.
Published: 6 May 2021
by Elsevier BV
Engineering Applications of Artificial Intelligence, Volume 102; https://doi.org/10.1016/j.engappai.2021.104286
The publisher has not yet granted permission to display this abstract.
Published: 4 January 2021
AIAA Scitech 2021 Forum; https://doi.org/10.2514/6.2021-0812
Conference: AIAA Scitech 2021 Forum
Several reports forecast a very high demand for Urban Air Mobility services such as package delivery and air taxi. This would lead to very dense low-altitude operations which cannot be safely accommodated by the current air traffic management system. Many different architectures for low-altitude air traffic management have been proposed in the literature, however, the lack of a common framework makes it difficult to compare strategies. The work presented here establishes efficiency, safety and capacity metrics, defines the components of an automated traffic management system architecture and introduces a preliminary framework to compare different alternatives. This common framework allows for the evaluation and comparison of different alternatives for unmanned traffic management. The framework is showcased on different strategies with different architectures. The impact of algorithmic choices and airspace architectures is evaluated. A decoupled approach to 4D trajectory planning is shown to scale poorly with agents density. The impact of segregating traffic by heading is shown to be very different depending on the algorithms and airspace access rules chosen.
Published: 27 August 2020
Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, Volume 235, pp 621-645; https://doi.org/10.1177/0954410020953045
With the increasing density level of airspace, the flawed logic of resolution in air conflict has become a potential hazard to keep flight safety for civil aviation. A powerful decision-support system is needed to identify and resolve potential conflicts on planned trajectory in advance. Existing studies on this subject mainly focus on the centralized means, but seldom consider the decentralized approaches. In this paper, a decentralized method is proposed so that each aircraft can generate the collision-free Reference Business Trajectory (RBT) autonomously, and resolve potential conflicts while conforming to the unified rules. Firstly, a Synchronous Discrete-Time-Discrete-Space trajectory modeling is developed to divide the continuous planned trajectory into multiple trajectory segments according to motion state. Thus, the collision can be accurately located at one certain risky segment, and the corresponding collision time can be acquired precisely. Through a weight analysis of collision time, the critical trajectory segment is determined to implement the task of conflict resolution. Then, the Optimal Reciprocal Collision Avoidance (ORCA) algorithm is adopted and extended to determine the collision-free maneuver with the consideration of direction selectivity. At last, the Trajectory Change Points (TCPs) are achieved by the quadratic program for each aircraft. The proposed method can help aircraft generate collision-free RBT in decentralized way successfully. Several simulations are conducted to confirm the validity and efficiency of the proposed approach.
CEAS Aeronautical Journal, Volume 11, pp 309-320; https://doi.org/10.1007/s13272-019-00400-6
The publisher has not yet granted permission to display this abstract.
Transportation Research Procedia, Volume 43, pp 309-318; https://doi.org/10.1016/j.trpro.2019.12.046
This paper presents results gained within the MoNIfly project, an EU funded research project to investigate a low-level unmanned traffic management system. With the use of the mobile network infrastructure, MoNIfly is contributing to a safe and socially acceptable integration of remotely piloted aircraft systems (RPAS) into existing airspace and urban areas. This requires RPAS to respect privacy and safety of the general public and all airspace users. MoNIfly proposes to equip all RPAS with a communications module, enabling to transmit data via the mobile network infrastructure. With the positional data gained that way, the proposed centralized UTM Management Software can issue warnings and evasive manoeuvres. In this paper, an algorithm for automatic cooperative separation among remotely piloted aircraft system and other air traffic is presented. This algorithm will make use of the existing infrastructure as well as vehicle communications developed in this project. The algorithm is based on the concept of modified velocity obstacles. In this work, the algorithm is introduced and evaluated in both a two-dimensional and a three-dimensional version, based on simulations of RPAS in different traffic densities. The results of this work will be a basis for optimizations and modifications towards a prototype development. Since the proposed algorithms will be demonstrated in field tests within the scope of the MoNIfly project, this paper also presents challenges and requirements for the transfer and the implementation of these methods for real flight tests.
Published: 1 March 2017
Journal of Guidance, Control, and Dynamics, Volume 40, pp 1-13; https://doi.org/10.2514/1.G000691
In a trajectory-based operations’ environment, at some time during the planning phase, shared business trajectories will become reference business trajectories, and not necessarily conflict free. This paper presents a way of obtaining a conflict-free solution for all planned trajectories during the strategic phase (before becoming reference business trajectories). The proposed methodology incorporates 1) a data-driven conflict-resolution model, and 2) a multiobjective global optimization that considers the interests of a variety of actors in the air traffic management community: particularly, air navigation service providers and airlines.
Published: 1 September 2016
2016 IEEE/AIAA 35th Digital Avionics Systems Conference (DASC) pp 1-7; https://doi.org/10.1109/dasc.2016.7778052
Conference: 2016 IEEE/AIAA 35th Digital Avionics Systems Conference (DASC), 2016-9-25 - 2016-9-29, Sacramento, United States
In this article, we test a horizontal detect and avoid algorithm for UASs flying in Terminal Control Areas. We have used recorded commercial traffic trajectories and randomly built thousands of conflict scenarios with UASs to check the ability of such an algorithm to ensure the separation with commercial aviation. We consider two different types of UASs, flying at 80kn or 160kn, with six different missions: flying straight or turning and leveled, climbing or descending. We only focus on horizontal maneuvers at constant speed in order to not interfere with the TCASs of aircraft, nor rely on most UASs poor ability to change speed. The article investigates the influence of the various parameters on the separation achieved and the amount of maneuvers required, especially the strategy used to select the best maneuver among the allowed headings. The analysis of our results shows that, amid two basic and “extreme” strategies that favor either minimal heading changes or the robustness of the maneuvers, the combination of both, switching from the first one to the second whenever the distance between the UAS and aircraft falls under a given threshold, gives the best results with very few remaining airproxes, while keeping low the amount and amplitude of maneuvers.