scholarly journals Review of Conflict Resolution Methods for Manned and Unmanned Aviation

Aerospace ◽  
2020 ◽  
Vol 7 (6) ◽  
pp. 79
Author(s):  
Marta Ribeiro ◽  
Joost Ellerbroek ◽  
Jacco Hoekstra
Keyword(s):  
Conflict Resolution ◽  
Air Transportation ◽  
Fast Time ◽  
Simulation Platform ◽  
Distributed Framework ◽  
Conflict Detection And Resolution ◽  
New Research ◽  
New Applications ◽  
Test Scenarios ◽  
Control Trajectory

Current investigations into urban aerial mobility, as well as the continuing growth of global air transportation, have renewed interest in Conflict Detection and Resolution (CD&R) methods. With the new applications of drones, and the implications of a profoundly different urban airspace, new demands are placed on such algorithms, further spurring new research. This paper presents a review of current CR methods for both manned and unmanned aviation. It presents a taxonomy that categorises algorithms in terms of their approach to avoidance planning, surveillance, control, trajectory propagation, predictability assumption, resolution manoeuvre, multi-actor conflict resolution, considered obstacle types, optimization, and method category. More than a hundred CR methods were considered, showing how most work on a tactical, distributed framework. To enable a reliable comparison between methods, this paper argues that an open and ideally common simulation platform, common test scenarios, and common metrics are required. This paper presents an overview of four CR algorithms, each representing a commonly used CR algorithm category. Both manned and unmanned scenarios were tested, through fast-time simulations on an open-source airspace simulation platform.

scholarly journals Velocity Obstacle Based Conflict Avoidance in Urban Environment with Variable Speed Limit

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 93
Author(s):  
Marta Ribeiro ◽  
Joost Ellerbroek ◽  
Jacco Hoekstra
Keyword(s):  
Conflict Resolution ◽  
Conflict Detection ◽  
Fast Time ◽  
Variable Speed ◽  
Variable Speed Limit ◽  
Package Delivery ◽  
Learning Agent ◽  
Variable Speed Limits ◽  
Conflict Detection And Resolution ◽  
Velocity Obstacle

Current investigations into urban aerial mobility, as well as the continuing growth of global air transportation, have renewed interest in conflict detection and resolution (CD&R) methods. The use of drones for applications such as package delivery, would result in traffic densities that are orders of magnitude higher than those currently observed in manned aviation. Such densities do not only make automated conflict detection and resolution a necessity, but will also force a re-evaluation of aspects such as coordination vs. priority, or state vs. intent. This paper looks into enabling a safe introduction of drones into urban airspace by setting travelling rules in the operating airspace which benefit tactical conflict resolution. First, conflicts resulting from changes of direction are added to conflict resolution with intent trajectory propagation. Second, the likelihood of aircraft with opposing headings meeting in conflict is reduced by separating traffic into different layers per heading–altitude rules. Guidelines are set in place to make sure aircraft respect the heading ranges allowed at every crossed layer. Finally, we use a reinforcement learning agent to implement variable speed limits towards creating a more homogeneous traffic situation between cruising and climbing/descending aircraft. The effects of all of these variables were tested through fast-time simulations on an open source airspace simulation platform. Results showed that we were able to improve the operational safety of several scenarios.

A PARALLEL ARCHITECTURE FOR AI NONLINEAR PLANNING

1990 ◽  
Vol 04 (02) ◽  
pp. 215-232 ◽  
Author(s):  
SUKHAN LEE ◽  
KYUSIK CHUNG
Keyword(s):  
Conflict Resolution ◽  
Distributed Processing ◽  
Parallel Architecture ◽  
State Level ◽  
Conflict Detection ◽  
Parallel And Distributed Processing ◽  
Resource Level ◽  
Planning Algorithm ◽  
Conflict Detection And Resolution ◽  
Nonlinear Planning

This paper presents a resource-level conflict detection and conflict resolution scheme which is combined with a state-level backward planning algorithm and provides efficient conflict detection and global conflict resolution for nonlinear planning. The scheme keeps track of the usage of individual resources during planning, and constructs a Resource-Usage Flow (RUF) structure (based on which conflict detection and resolution is accomplished). The RUF structure allows the system to perform minimal and nonredundant operations for conflict detection and resolution. Furthermore, resource-level conflict detection and resolution facilitates problem decomposition in terms of resources, thereby providing easy implementation in a parallel and distributed processing environment. Performance analysis indicates that the proposed architecture has a speed-up factor of the average depth of a plan network, D(Na), compared to the distributed NOAH, where Na (the total number of action nodes at the completion of planning) and D(Na) are considerably larger than the number of resources involved in planning as well as the number of initial goal states.

Liquid-metal magnetohydrodynamics with strong magnetic fields: a report on Euromech 70

1976 ◽  
Vol 78 (2) ◽  
pp. 261-288 ◽  
Author(s):  
J. C. R. Hunt ◽  
R. Moreau
Keyword(s):  
Magnetic Fields ◽  
Liquid Metal ◽  
Flow Measurement ◽  
Industrial Applications ◽  
Two Phase ◽  
Solid Objects ◽  
Research Problems ◽  
Research Findings ◽  
New Research ◽  
New Applications

This paper is a summary of the first Euromech Colloquium to be held on Magnetohydrodynamics (MHD). It was organized in conjunction with the Centre National de la Recherche Scientifique and held at Grenoble from 16–19 March 1976 with 60 participants from 10 countries present. Papers were presented on laminar and turbulent MHD duct flows; heat transfer and two-phase flows in MHD; the effects of magnetic fields on instabilities and turbulence; the motion of and forces on solid objects in MHD flows; flow-measurement methods, and applications of MHD in the metallurgical industries, in sodium technology and in liquid-metal power generation. Our main conclusion is that there are many industrial applications of the existing body of research findings in MHD, but that quite new research problems have arisen as a result of the new applications, and that these need investigation. MHD lives!

scholarly journals Active molecular plasmonics: tuning surface plasmon resonances by exploiting molecular dimensions

Nanophotonics ◽  
2015 ◽  
Vol 4 (1) ◽  
pp. 186-197 ◽  
Author(s):  
Kai Chen ◽  
Eunice Sok Ping Leong ◽  
Michael Rukavina ◽  
Tadaaki Nagao ◽  
Yan Jun Liu ◽  
...  
Keyword(s):  
Electric Fields ◽  
Self Assembly ◽  
Molecular Design ◽  
Research Area ◽  
Metal Nanostructures ◽  
Surface Plasmon Resonances ◽  
Challenges And Opportunities ◽  
New Research ◽  
New Applications ◽  
External Stimuli

Abstract:Molecular plasmonics explores and exploits the molecule–plasmon interactions on metal nanostructures to harness light at the nanoscale for nanophotonic spectroscopy and devices. With the functional molecules and polymers that change their structural, electrical, and/or optical properties in response to external stimuli such as electric fields and light, one can dynamically tune the plasmonic properties for enhanced or new applications, leading to a new research area known as active molecular plasmonics (AMP). Recent progress in molecular design, tailored synthesis, and self-assembly has enabled a variety of scenarios of plasmonic tuning for a broad range of AMP applications. Dimension (i.e., zero-, two-, and threedimensional) of the molecules on metal nanostructures has proved to be an effective indicator for defining the specific scenarios. In this review article, we focus on structuring the field of AMP based on the dimension of molecules and discussing the state of the art of AMP. Our perspective on the upcoming challenges and opportunities in the emerging field of AMP is also included.

scholarly journals Constructing Scenarios’ Network-of-Flight Conflict in Approach of Intersecting Runway

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ming Cheng ◽  
Yixuan Li ◽  
Xiaolian Han
Keyword(s):  
Conflict Resolution ◽  
Complex Network ◽  
Network Model ◽  
Control Strategy ◽  
General Rule ◽  
Closeness Centrality ◽  
Degree Centrality ◽  
Operational Risks ◽  
New Research

For studying the mechanism of flight conflict in approach of the intersecting runway, this paper applies the case study, scenario construction, and complex network, analyzes the operational risks of the intersecting runway, and researches the general rule of flight conflict. We constructed a network model of scenario evolution of flight conflict with selecting Beijing Daxing International Airport as the research object, which included 169 nodes and 263 edges. It proposed path evolution and verified the effectiveness of this network. We analyzed the degree centrality, median centrality, and closeness centrality of the network, and the results showed that the comprehensive value of 5 nodes is high, including go-around (V2), conflict resolution (C22), the warning light of aft cargo dJor was extinguished (F12), suspend subsequent take-off operations (F5), and keeping visual flying (C26). The results show that this method provides a new research way for the control strategy of chain breakage and the mechanism of scenario evolution of flight conflict.

A Distributed Systems Approach to Airborne Self-Separation

2010 ◽  
pp. 215-236
Author(s):  
Henrique Moniz ◽  
Alessandra Tedeschi ◽  
Nuno Ferreira Neves ◽  
Miguel Correia
Keyword(s):  
Game Theory ◽  
Conflict Resolution ◽  
Distributed Systems ◽  
Distributed Computing ◽  
Systems Approach ◽  
Air Transportation ◽  
Distributed Protocols ◽  
Different Types ◽  
Resolution Algorithm

This chapter introduces the reader to the benefits of distributed computing in air transportation. It presents a solution to airborne self-separation based on RAPTOR, a stack of distributed protocols that allows aircraft to reach different types of agreement in the presence of faults, both of accidental and malicious nature. These protocols are used as primitives to implement specific services for airborne self-separation, which are created within the context of a conflict resolution algorithm based on game theory.

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