Energy-efficient resource management for continuous scenario fulfillment by UAV fleets

Unbemannte Luftfahrzeuge (unmanned aerial vehicles, UAV) sind autonom fliegende und flexibel einsetzbare mobile Roboter, welche durch ihre große Flexibilität und Erweiterbarkeit viele Möglichkeiten bieten. Insbesondere im Bereich der Katastrophenbewältigung erlangen sie immer stärkere Bedeutung, da die Aufgaben zur Aufklärung im Gebiet und zur Erschaffung einer Kommunikationsinfrastruktur ungebunden und schnell durch sie bewältigt werden können. Der Forschungsschwerpunkt dieser Arbeit liegt in der Herausforderung der Ressourcenverwaltung in einem solchen Szenario. Während die Priorität des UAV Einsatzes klar darin besteht die Katastrophenbekämpfung unterbrechungsfrei zu unterstützten, muss ebenso auf die Verwaltung limitierter Ressourcen, wie elektrischer Energie, eingegangen werden. Wir präsentieren ein entsprechendes Systemdesign einer Ressourcenverwaltung und Strategien zur Verbesserung der Leistung und damit zur Erhöhung der Energieeffizienz des Gesamtsystems. Die Implementierung und gründliche Untersuchung eines solchen komplexen Systems von Teilsystemen ist verbunden mit hohen finanziellen Kosten, großem Test-Risiko und einer langen Entwicklungsdauer. Aus diesem Grund setzt diese Arbeit auf abstrakte ausführbare Modelle der Umgebung, des Verwaltungssystems und der UAVs. Die Verwendung dieser Modelle in einer Massensimulation mit beliebiger Komplexität und Konfiguration ermöglicht die schnelle und kostengünstige Verifikation der Funktionstüchtigkeit und die Bewertung verschiedener Verwaltungsstrategien. Im Vergleich zu der präsentierten trivialen Lösung ist die entwickelte verbesserte Lösung in der Lage den zeitlichen Anteil einzelner UAVs im Missionseinsatz zu erhöhen und die insgesamt nötige Menge an UAVs für die dauerhafte Abdeckung aller Aufgaben zu reduzieren. Die Schritte zur Optimierung reduzierten im analysierten Beispiel den Gesamtenergiebedarf aller UAVs um nahezu 20 Prozent.Unmanned aerial vehicles (UAV) are autonomous and flexible robotic systems with a remarkable degree of freedom and extendibility. They are especially valuable in the context of disaster scenarios, where arising use cases for reconnaissance and mobile communication infrastructure creation have to be addressed rapidly and unbound from restrictions in the operation field. The research focus of this thesis lies in the challenge of resource management during such an application. While the priority of the UAV utilization lies on uninterrupted task execution, concern for limited resources, like electrical energy, and resultant maintenance processes has to be dealt with on a lower management layer. We present a resource management system design and multiple competing strategies to improve its performance and overall energy efficiency. The implementation and thorough evaluation of such a complex system of systems is linked to high costs, great operational risks, and a long development time. For that reason, we developed executable models representing the environment, the resource management system, and the UAV. Through mass simulation of these models in various scenario constellations and configurations, we are able to verify the applicability of our proposed resource management system and to evaluate and optimize various aspects of its processes. In comparison to a presented trivial solution, we are able to increase the UAV flight utilization efficiency and decrease the needed amount of provided UAVs in the scenario. Our optimization efforts reduce the overall energy demand of UAVs in the analyzed example scenario by almost 20 percent

Design and Implementation of a Novel Multicopter Unmanned Aircraft System for Quantitative Studies of the Atmosphere

The call for creating new innovative meteorological instruments to help fulfill observational gaps in the atmospheric sciences has been gaining strength in the past few years. This comes along with the urgent need to increase the understanding of fast-evolving atmospheric processes to subsequently provide accurate and reliable weather forecasts in a timely manner. The increased interest in obtaining atmospheric observations with higher spatio-temporal resolution pushed scientists to begin exploring and harnessing new leading-edge engineering technology. For instance, affordable and accessible Unmanned Aircraft Systems (UASs) technology emerged within this timeframe and has since evolved rapidly. Many researchers and institutions have agreed that UASs are promising technology candidates for targeted in situ weather sampling, which has the potential to meet the stringent meteorological measurement requirements. However, the current market has shifted and shaped UASs for other applications that may be unsuitable or suboptimal for weather sampling. Special considerations were examined in this study to conceptualize a specialized weather UAS (WxUAS) capable of collecting reliable thermodynamic and kinematic measurements. While also performing similarly to conventional weather instruments, such as radiosondes, Doppler wind lidars, and meteorological towers, as well as providing a complementary role whenever measurement limitations arise. Therefore, given that the exploration of integrating weather instrumentation into UAS is rare, it is hypothesized that atmospheric measurements of a modified multicopter UAS that minimizes platform-induced errors can fill the thermodynamic and kinematic data gap in the planetary boundary layer (PBL). The proposed solution is a UAS-based in situ vertical profiler system, dubbed the CopterSonde, with necessary weather instrumentation, adequate sensor placement, and useful flight functions for optimal sampling of undisturbed air. This solution attempts to provide a holistic WxUAS design where the UAS itself was adapted to become not just a payload carrier but also part of the weather instrumentation system. Flow simulation studies backed with observations in the field were used to address sensor siting and mitigate sources of thermodynamic errors. Moreover, techniques for thermodynamic measurement correction, adaptable flight behavior, and 3D wind estimation were implemented using the experimental CopterSonde concept with results comparable to widely accepted conventional weather instruments. Additionally, the platform reliability was successfully demonstrated in different challenging environments, from freezing temperatures in Hailuoto, Finland, to high elevations in Colorado, USA. A robust concept of operation and decision-making algorithms were established to ensure safe flights during demanding field campaigns. As a result, the National Oceanic and Atmospheric Administration (NOAA) in the USA has recognized the CopterSonde as part of the approved UAS fleet for NOAA-related missions. Overall, the engineering advances shown in this work helped to produce an optimized UAS capable of collecting targeted and reliable weather observations. Even though the CopterSonde is an experimental design, this work can be used as a guideline to define future standards for WxUAS development and deployment

Minimum Cost Design of Cellular Networks in Rural Areas with UAVs, Optical Rings, Solar Panels and Batteries

Bringing the cellular connectivity in rural zones is a big challenge, due to the large installation costs that are incurred when a legacy cellular network based on fixed Base Stations (BSs) is deployed. To tackle this aspect, we consider an alternative architecture composed of UAV-based BSs to provide cellular coverage, ground sites to connect the UAVs with the rest of the network, Solar Panels (SPs) and batteries to recharge the UAVs and to power the ground sites, and a ring of optical fiber links to connect the installed sites. We then target the minimization of the installation costs for the considered UAV-based cellular architecture, by taking into account the constraints of UAVs coverage, SPs energy consumption, levels of the batteries and the deployment of the optical ring. After providing the problem formulation, we derive an innovative methodology to ensure that a single ring of installed optical fibers is deployed. Moreover, we propose a new algorithm, called DIARIZE, to practically tackle the problem. Our results, obtained over a set of representative rural scenarios, show that DIARIZE performs very close to the optimal solution, and in general outperforms a reference design based on fixed BSs

Theoretical, numerical, and experimental methodologies for structural analysis of polymeric aeronautical elements produced via additive manufacturing

L'abstract è presente nell'allegato / the abstract is in the attachmen

Aerial Network Assistance Systems for Post-Disaster Scenarios : Topology Monitoring and Communication Support in Infrastructure-Independent Networks

Communication anytime and anywhere is necessary for our modern society to function. However, the critical network infrastructure quickly fails in the face of a disaster and leaves the affected population without means of communication. This lack can be overcome by smartphone-based emergency communication systems, based on infrastructure-independent networks like Delay-Tolerant Networks (DTNs). DTNs, however, suffer from short device-to-device link distances and, thus, require multi-hop routing or data ferries between disjunct parts of the network. In disaster scenarios, this fragmentation is particularly severe because of the highly clustered human mobility behavior. Nevertheless, aerial communication support systems can connect local network clusters by utilizing Unmanned Aerial Vehicles (UAVs) as data ferries. To facilitate situation-aware and adaptive communication support, knowledge of the network topology, the identification of missing communication links, and the constant reassessment of dynamic disasters are required. These requirements are usually neglected, despite existing approaches to aerial monitoring systems capable of detecting devices and networks. In this dissertation, we, therefore, facilitate the coexistence of aerial topology monitoring and communications support mechanisms in an autonomous Aerial Network Assistance System for infrastructure-independent networks as our first contribution. To enable system adaptations to unknown and dynamic disaster situations, our second contribution addresses the collection, processing, and utilization of topology information. For one thing, we introduce cooperative monitoring approaches to include the DTN in the monitoring process. Furthermore, we apply novel approaches for data aggregation and network cluster estimation to facilitate the continuous assessment of topology information and an appropriate system adaptation. Based on this, we introduce an adaptive topology-aware routing approach to reroute UAVs and increase the coverage of disconnected nodes outside clusters. We generalize our contributions by integrating them into a simulation framework, creating an evaluation platform for autonomous aerial systems as our third contribution. We further increase the expressiveness of our aerial system evaluation, by adding movement models for multicopter aircraft combined with power consumption models based on real-world measurements. Additionally, we improve the disaster simulation by generalizing civilian disaster mobility based on a real-world field test. With a prototypical system implementation, we extensively evaluate our contributions and show the significant benefits of cooperative monitoring and topology-aware routing, respectively. We highlight the importance of continuous and integrated topology monitoring for aerial communications support and demonstrate its necessity for an adaptive and long-term disaster deployment. In conclusion, the contributions of this dissertation enable the usage of autonomous Aerial Network Assistance Systems and their adaptability in dynamic disaster scenarios

"Nah, musing is fine. You don't have to be 'doing science'": emotional and descriptive meaning-making in online non-professional discussions about science

In this thesis I use online settings to explore how descriptive and emotional forms of meaning-making interact in non-professional discussions around ‘science’. Data was collected from four participatory online fora, from March 2015 to February 2016. Posts and comments from these fora were examined through discourse analysis, supplemented by interviews with participants and computer-aided text analysis, over the period August 2015 to August 2017. Theoretical background drew on Science and Technology Studies (STS) and Fan Studies (FS), to examine how science was presented in both descriptive and emotional terms. There were two main findings. Firstly, discussions were shaped by an expectation that members should respect mainstream scientific consensus. In a manner familiar from STS, participants treated claims which went against scientific consensus as incorrect or noncredible. Responses also showed emotional aspects which shaped participation. Respect for scientific consensus facilitated social bonding and expression of community values, while disrespect was met with anger and/or ridicule. Through normalisation of such behaviour, scientific authority was maintained by communal sanctions rather than accredited expertise. The second main finding was a distinction between two forms of discourse, which I refer to as musing and identifying. In musing, participants focussed on specific phenomena, technologies and science-related concepts. Emotional language in such discourse was generally positive, but explicit mentions of people were rare. In identifying, participants reflected on processes of discussing and making/assessing claims; in doing so they foregrounded references to people. Emotional references in identifying tended to involve frustration, concern, and scorn. These findings develop STS understanding of how engagement with science takes place outside of professional research, communication, and/or education; and, more broadly, how discourse around science can be shaped by emotional attachments and informal norms. This thesis also contributes a discourse analytic perspective to recent debates around the interaction of expertise and emotion online

Proceedings of the International Micro Air Vehicles Conference and Flight Competition 2017 (IMAV 2017)

The IMAV 2017 conference has been held at ISAE-SUPAERO, Toulouse, France from Sept. 18 to Sept. 21, 2017. More than 250 participants coming from 30 different countries worldwide have presented their latest research activities in the field of drones. 38 papers have been presented during the conference including various topics such as Aerodynamics, Aeroacoustics, Propulsion, Autopilots, Sensors, Communication systems, Mission planning techniques, Artificial Intelligence, Human-machine cooperation as applied to drones

Radar Imaging in Challenging Scenarios from Smart and Flexible Platforms

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Review of hybrid electric powered aircraft, its conceptual design and energy management methodologies

The paper overviews the state-of-art of aircraft powered by hybrid electric propulsion systems. The research status of the design and energy management of hybrid aircraft and hybrid propulsion systems are further reviewed. The first contribution of the review is to demonstrate that, in the context of relatively underdeveloped electrical storage technologies, the study of mid-scale hybrid aircraft can contribute the most to both theoretical and practical knowledge. Meanwhile, the profits and potential drawbacks of applying hybrid propulsion to mid-scale hybrid airplanes have not been thoroughly illustrated. Secondly, as summed in the overview of design methodologies, the multi-objective optimization transcends the single-objective one. The potential of the hybrid propulsion system can be thoroughly evaluated in only one optimization run, if several objectives optimized simultaneously. Yet there are few researches covering the conceptual design of hybrid aircraft using multi-objective optimization. The review of the most popular energy management strategies discloses the third research gap—current methodologies favoured in hybrid ground vehicles do not consider the aircraft safety. Additionally, both non-causal and causal energy management are needed for performing a complicated flight mission with several sub-tasks