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This paper discusses the design and evaluation of an efficient safe flight envelope protection method for keeping an augmented aircraft with manual flight control laws within the safe envelope bounds. This flight envelope is estimated adaptively, so that configuration changes and possible failures can be taken into account. The updated information of the safe envelope is used in the flight control laws to prevent loss of control in flight It has been found that a control architecture involving separate pilot command filtering is particularly well suited to incorporate these adaptive protections. Moreover, haptic feedback to the pilot controls can be included as well, based on the same adaptive bounds. This has the potential to further increase the flight crew awareness about the risk of losing control in flight. These algorithms have been evaluated in the Simulation, Motion, and Navigation Research Simulator at Delft University of Technology to investigate the impact on the awareness of the crew. Commercial airline crews flew multiple challenging approach and landing scenarios in a relevant simulated environment. Results show that the algorithms support the flight crew significantly. They contribute to "carefree" flying and to avoiding loss of control in flight. [ABSTRACT FROM AUTHOR]

The work that is presented in this paper is part of an ongoing study on the relationship between airspace structure and capacity. The present paper investigates the degree of structuring needed to maximize capacity for decentralized en route airspace. To this end, four decentralized en route airspace concepts, which vary in terms of the number of constrained degrees of freedom, were compared using fast-time simulations, for both nominal and non-nominal conditions. The airspace structure-capacity relationship was studied from the effect of multiple traffic demand densities on airspace metrics. The results indicated that structuring methods that overconstrained the horizontal path of aircraft reduced capacity because traffic demand displays no predominant patterns in the horizontal dimension for decentralization. The results also showed that capacity was maximized when a vertical segmentation of airspace was used to separate traffic with different travel directions at different flight levels. This mode of structuring improved performance over completely unstructured airspace by reducing relative velocities between aircraft cruising at the same altitude, while allowing direct horizontal routes. [ABSTRACT FROM AUTHOR]

This paper proposes a novel avoidance method called the three-dimensional velocity obstacle method. The method is designed for unmanned aerial vehicle applications, in particular to autonomously handle uncoordinated multiple encounters in an integrated airspace, by exploiting the limited space in a three-dimensional manner. The method is a three-dimensional extension of the velocity obstacle method that can reactively generate an avoidance maneuver by changing the vehicle velocity vector based on the encounter geometry. Adverse maneuvers of the obstacle are anticipated by introducing the concept of a buffer velocity set, which ensures that the ownship will diverge with sufficient space in case of sudden imminence. A three-dimensional resolution is generated by choosing the right plane for avoidance, in which the unmanned aerial vehicle conducts a pure turning maneuver. Implementation of the three- dimensional velocity obstacle method is tested in several simulations that demonstrate its capability to resolve various three-dimensional conflicts. A validation using Monte Carlo simulations is also conducted in stressful superconflict scenarios, which results in zero collisions occurrences for the entire 25,000 samples. [ABSTRACT FROM AUTHOR]

The article discusses a study which proposed a selective velocity obstacle (SVO) method for deconflicting maneuvers applied to unmanned aerial vehicles. Topics discussed include the original concept of the velocity obstacle method, the incorporation of the right-of-way rules, and avoidance algorithm and the minimum avoidance turning rate. Information is also presented on a MATLAB program intended to evaluate the SVO method.

Driven by rising consumer demand, interest is growing in the application of autonomous unmanned aerial vehicles (drones) for the last-mile delivery of small express packages and fast-food meals in cities. To be realised, this would require the Very Low Level (VLL) urban airspace to be able to cope with high traffic densities of commercial delivery drones. The potential benefits of such novel drone-based applications are a reduction of traffic congestion in cities, lower greenhouse gas emissions and more efficient transportation operations. To help realise this concept, programs such as U-Space, the unmanned traffic management system for Europe, are developing important services such as deconfliction management and dynamic capacity management. However, for several of these services, design choices will depend on how, and how extensive they will be used. It therefore becomes important to estimate how many delivery drones would operate in a typical city. This paper aims to provide an estimate by establishing a framework to determine the traffic demand for express drone-based package delivery of five European countries. In addition, a detailed case-study is presented for determining traffic density of express package drone delivery for Paris metropolitan area in order to assess the feasibility from a user's perspective. The paper also discusses the potential of fast-food meal delivery drones compared to traditional delivery modes for Paris. Results suggest that hourly traffic densities culminating from express package and fast-food meal delivery drones will exceed today's global commercial aircraft traffic of 10,000 per day by more than six-fold for just one potential metropolitan city. • Drone-based delivery of small express packages could positively impact urban transportation. • Delivery of small packages via autonomous drones could potentially be delivered faster and cheaper than current transport modes. • By 2035, the metropolitan area of Paris could potentially expect 63,596 drone-based deliveries within an area of 12,012km2. • High-density traffic operations in urban areas will create challenges to Unmanned Traffic Management systems. • Adequate protocols and robust airspace design measures should be urgently addressed by U-Space policymakers. [ABSTRACT FROM AUTHOR]