This article is a technical report on the two different guidance systems based on vector fields that can be found in Paparazzi, a free sw/hw autopilot. Guiding vector fields allow autonomous vehicles to track paths described by the user mathematically. In particular, we allow two descriptions of the path with an implicit or a parametric function. Each description is associated with its corresponding guiding vector field algorithm. The implementations of the two algorithms are light enough to be run in a modern microcontroller. We will cover the basic theory on how they work, how a user can implement its own paths in Paparazzi, how to exploit them to coordinate multiple...

The integration of Unmanned Aircraft Systems into the airspace is a challenging, complex task for both operators and regulators. To ensure a safe and secure UAS integration, they should rely on wide variety of dependable subsystems , including a tracking and position reporting system. This paper proposes a system architecture for tracking and position reporting of UAS in very-low level airspace. The system leverages low-latency communications and distributed computing to offer highly available, consistent tracking information. Preliminary results suggest that our approach is especially useful for the traffic management and operations in densely populated areas.

With the continuous growth in the air transportation demand, air traffic controllers will have to handle increased traffic and consequently, more potential conflicts. This gives rise to the need for conflict resolution advisory tools that can perform well in high-density traffic scenarios given a noisy environment. Unlike model-based approaches, learning-based approaches can take advantage of historical traffic data and flexibly encapsulate environmental uncertainty. In this study, we propose a reinforcement learning approach that is capable of resolving conflicts, in the presence of traffic and inherent uncertainties in conflict resolution maneuvers, without the need for...

Drones are commonly used for many civil applications and the procedures to operate them have evolved during the past years to make them accessible to those with limited piloting skills in several scenarios. However, the deployment of a fleet in the context of scientific research can lead to complex situations that require an important preparation in terms of logistics, permission to fly from authorities, and coordination during the flights. This paper is a field report of the flight campaign held end of January 2020 at the Barbados Island as part of the NEPHELAE project. The main objectives of the project were to fly into trade wind cumulus clouds to understand the...

n high-density Urban Air Mobility (UAM) operations, reducing congestion and structural constraints are key challenges. Pioneering urban airspace design projects expect the air vehicles to fit into structured UAM corridor networks. However, most existing air transport networks are not capable of handling the increasing traÿc demand, which is likely to cause congestion, traÿc complexity, and safety issues. To adapt the increasing demand to the current airspace capacity, a novel macroscopic traÿc assignment model is proposed to mitigate the congestion and organize the structure of air traÿc flow. Firstly, the UAM corridor is designed and fitted into graph representation...

Sensitivity indices are commonly used to quantify the relative influence of any specific group of input variables on the output of a computer code. One crucial question is then to decide whether a given set of variables has a significant impact on the output. Sobol indices are often used to measure this impact but their estimation can be difficult as they usually require a particular design of experiment. In this work, we take advantage of the monotonicity of Sobol indices with respect to set inclusion to test the influence of some of the input variables. The method does not rely on a direct estimation of the Sobol indices and can be performed under classical iid sampling...

This article proposes a discussion on the strengths, weaknesses, opportunities, and threats related to the deployment of QUIC end-to-end from a satellite-operator point-of-view. The deployment of QUIC is an opportunity for improving the quality of experience when exploiting satellite broadband accesses. Indeed, the fast establishment of secured connections reduces the transmission time of short files. Moreover, removing transport-layer performance-enhancing proxies reduces the cost of network infrastructures and improves the integration of satellite systems. However, the congestion and flow controls at end points are not always suitable for satellite communications due to...

A detailed experimental study of propeller-wing interaction was presented. Five-hole probe was used to obtain velocity distribution at a survey plane behind trailing edge of a high-aspect-ratio wing with tractor propeller. Significant deformation of propeller slipstream was observed compared to a free propeller. The deformation was more prominent at low advance ratio, where transition flight of vertical take-off / landing aircraft were concerned. Comparison with two recent reduced-order slipstream models revealed large discrepancies between theoretical predictions and wake survey results. An analytical model of slipstream transverse deformation was proposed at the end...

The use of a swarm of low-cost, mission-specific drones to form a Flying Ad-hoc Network (FANET) has literally become a ’hotspot’ in the drone community. A number of studies have been conducted on how to achieve a FANET, but few have considered the security perspectives of this subject. FANET’s unique features have made it difficult to strengthen its defense against ever-changing security threats. Today, more and more FANET applications are implemented into civil airspace, but the development of FANET security has remained unsatisfactory. In this paper, we try to address this issue by proposing a new Intrusion Detection System (IDS), an hybrid method based on both spectral...