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Submitted by Maike Costa (maiksebas@gmail.com) on 2017-07-03T12:25:38Z No. of bitstreams: 1 arquivototal.pdf: 3177649 bytes, checksum: b09cbb264ec1b770f1aa0bb04cc0fb8f (MD5) / Made available in DSpace on 2017-07-03T12:25:39Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3177649 bytes, checksum: b09cbb264ec1b770f1aa0bb04cc0fb8f (MD5) Previous issue date: 2017-04-04 / Systems using Unmanned Aerial Vehicles (UAV) are typical examples of cyber-physical systems. Designing such systems is not a trivial task because it brings the challenge of dealing with the uncertainty that is inherent to this type of system. Therefore, it is important the usage of appropriate tools for design that can ensure implementation of these systems with a certain level of confiability. Thus, the purpose of this work is to integrate two simulators via HLA in order to simulate and evaluate different flights strategies. For this, it is presented a simulation environment that can execute flight plans in order to evaluate different strategies in uncertain scenarios. The simulator was developed in Ptolemy and integrated with SITL/ArduPilot via HLA. The results show that with the use of the approach presented in this paper it is possible to obtain results closer to reality, thus more efficient flight strategies can be developed and evaluate. / Sistemas que utilizam Veículos Aéreos Não-Tripulados (VANT) são exemplos típicos de sistemas ciber-físicos. Projetar tais sistemas não é uma tarefa trivial porque traz consigo o desafio de lidar com a incerteza, que é algo inerente a este tipo de sistema. Por isso, é importante que o projeto seja feito com ferramentas apropriadas que possam viabilizar a execução desses sistemas com um certo nível de confiança para seus usuários. Deste modo, a proposta deste trabalho é unir dois simuladores, através do HLA, com o objetivo de simular e avaliar estratégias de voos mais próximas do ambiente de voo real. Para isso, foi construído um simulador onde é possível realizar diversos planos de voo com a finalidade de analisar diferentes estratégias em um ambiente provido de incertezas. O simulador foi desenvolvido na ferramenta Ptolemy e integrado, através do HLA, com o simulador SITL/ArduPilot. Os resultados mostram que com a utilização da abordagem defendida neste trabalho é possível obter resultados mais próximos da realidade, assim estratégias mais eficientes de voo podem ser desenvolvidas e avaliadas.

Med målet att landa fastvingedrönare på en liten yta utfördes ett projekt som implementerade en ballistisk landning i simulation. Projektet utfördes på initiativ av Sjöräddningssällskapet som har utvecklat en fastvingedrönare som behöver kunna landa på en båt. Projektet var en del av ett kandidatarbete inom ämnet programvaruteknik med syfte attbesvara hur landningen kunde skapa värde för kunden, vilka erfarenheter för framtidensom projektgruppen kunde dokumentera och vilket stöd projektgruppen fick från att använda en systemanatomi. För att besvara frågeställningarna utarbetade projektgruppen en kravspecifikation och ensystemanatomi samt utförde projektet med kontinuerliga utvärderingar under projektetsgång. Vid utvecklingen användes en variant av Scrum. Som resultat implementerades engrundläggande version av en ballistisk landning. Dokument skapades för utvecklingenoch gemensamma erfarenheter samlades in genom utvärderingar och möten. Projektgruppen fick många lärdomar om att arbeta i och planera större projekt vilket diskuteras i rapporten. Projektet och den utvecklade landningens hållbarhetsaspekter utvärderades.

The usage of unmanned aerial vehicles in applications such as terrain mapping and surveillance is proliferating in the modern world. This project aims to investigate the feasibility, in terms of payload capacity and stability, of small scale winged aircraft that have the ability to lift and land vertically, while also being able to transition to normal forward flight using wings for primary lift. The prototype aircraft was built with the limitation of using only one lift-producing motor that would be responsible for both vertical take-off and landing, and the horizontal propulsion in forward flight. The prototype was built primarily using 3D-printed plastic with an electric ducted fan as the method of propulsion. Internal ducting was used to redirect airflow downwards, from the only propulsion source to achieve vertical lift at a standstill. The final iteration of the aircraft successfully performed multiple hovers over 30 seconds long but did not have wings to test a transition to forward flight. Lifting capacity was low but the concept proposed in this thesis holds promise for further development and optimization. / Användningen av obemannade luftfarkoster för tillämpningar såsom terrängkartläggning och övervakning ökar i den moderna världen. Detta projekt syftar till att undersöka lämpligheten, i termer av lastkapacitet och stabilitet, för småskaliga vingade luftfarkoster som har förmågan att lyfta och landa vertikalt, samtidigt som de kan övergå till normal framåtflygning med vingar för primär lyftkraft. Prototypen av luftfarkosten byggdes med begränsningen att endast en lyftproducerande motor skulle användas, som skulle vara ansvarig för både vertikal lyftning och horisontell framdrivning vid framåtflygning. Prototypen byggdes främst med 3D-utskrivna plastkomponenter med en elektrisk innesluten fläkt som källa för dragkraft. Interna luftkanaler användes för att omdirigera luftflödet nedåt, från den enda lyftproducerande motorn, för att uppnå vertikal lyftkraft vid ett stillastående. Den slutliga versionen av luftfarkosten utförde flera svävningar i över 30 sekunder, men farkosten hade inga vingar för att testa övergången till framåtflygning. Lastkapaciteten var låg, men konceptet som föreslogs i denna avhandling är lovande för vidare utveckling och optimering.

In recent years, the use of rotorcraft uninhabited aerial vehicles (UAVs) for cargo delivery has become of particular interest to private companies and humanitarian organizations, namely due to their reduced operational costs, ability to reach remote locations and to take off and land vertically. The slung configuration, where the cargo is suspended below the vehicle by a cable, is slowly being favoured for its ability to transport different sized loads without the need for the vehicle to land. However, such configurations require complex control systems in order to stabilize the swing of the suspended load. The goal of this research is to design a control system which will be able to bring a slung payload transported by a rotorcraft UAV back to its stable equilibrium in the event of a disturbance. A simple model of the system is first derived from first principles for the purpose of simulating a control algorithm. A controller based in model-free, policy-gradient reinforcement learning is then derived and implemented on the simulator in order to tune the learning parameters and reach a first stable solution for load stabilization in a single plane. An experimental testbed is then constructed to test the performance of the controller in a practical setting. The testbed consists of a quadcopter carrying a weight suspended on a string and of a newly designed on-board load-angle sensing device, to allow the algorithm to operate using only on-board sensing and computation. While the load-angle sensing design was found to be sensitive to the aggressive manoeuvres of the vehicle and require reworking, the proposed control algorithm was found to successfully stabilize the slung payload and adapt in real-time to the dynamics of the physical testbed, accounting for model uncertainties. The algorithm also works within the framework of the widely-used, open-source autopilot program ArduCopter, making it straightforward to implement on existing rotorcraft platforms. In the future, improvements to the load angle sensor should be made to enable the algorithm to run fully on-board and allow the vehicle to operate outdoors. Further studies should also be conducted to limit the amount of vehicle drift observed during testing of the load stabilization.

The aim of this thesis is to modify commercially produced drone DJI Matrice 100 and replace its original control unit by open source Pixhawk and its accessories. Subsequently, it deals with the selection of suitable open source firmware for Pixhawk and its configuration on the device. Another part is dedicated to the possibilities of using the Robotic Operating System (ROS) and its Mavros libraries on the onboard computer Raspberry Pi. By using Mavros, it examines the possibilities of drone flight control, both in the simulation environment and in the real environment.

Die Auswahl an Hardware und Software auf dem Drohnen-Markt nimmt stetig zu. Autopilot-Software wie z. B. ArduCopter bietet bereits die Möglichkeit eine vor dem Flug definierte Liste von Wegpunkten automatisiert abzufliegen. Im Rahmen dieser Arbeit wird eine Software entwickelt, die dynamische Flugroutenplanung ermöglicht. Befindet sich beispielsweise ein Hindernis auf der aktuellen Flugbahn, berechnet ein Pfadplanungsalgorithmus eine neue Route ohne Kollision um dieses Hindernis herum.

Fixed-wing unmanned aerial vehicles (UAVs) with the ability to hover combine the speed and endurance of traditional fixed-wing fight with the stable hovering and vertical takeoff and landing (VTOL) capabilities of helicopters and quadrotors. This combination of abilities can provide strategic advantages for UAV operators, especially when operating in urban environments where the airspace may be crowded with obstacles. Traditionally, fixed-wing UAVs with hovering capabilities had to be custom designed for specific payloads and missions, often requiring custom autopilots and unconventional airframe configurations. With recent government spending cuts, UAV operators like the military and law enforcement agencies have been urging UAV developers to make their aircraft cheaper, more versatile, and easier to repair. This thesis discusses the use of the commercially available ArduPilot open source autopilot, to autonomously transition a fixed-wing UAV to and from hover flight. Software modifications were made to the ArduPilot firmware to add hover flight modes using both Proportional, Integral, Derivative (PID) Control and Model Reference Adaptive Control (MRAC) with the goal of making the controllers robust enough so that anyone in the ArduPilot community could use their own ArduPilot board and their own fixed-wing airframe (as long as it has enough power to maintain stable hover) to achieve autonomous hover after some simple gain tuning. Three new hover flight modes were developed and tested first in simulation and then in flight using an E-Flight Carbon Z Yak 54 RC aircraft model, which was equipped with an ArduPilot 2.5 autopilot board. Results from both the simulations and flight test experiments where the airplane transitions both to and from autonomous hover flight are presented.

The goal of this bachelor thesis has been to evaluate and test the available open source software and commercial hardwarefor potential later use as the electrical system in the ALPHAUAV. ALPHA is a student project, with the goal of building an autonomous drone capable of high altitude, long-endurance missions to gather data from electromagnetic phenomena in the atmosphere. Data later to be used in research at the facility ofSpace and Plasma physics at KTH. The evaluation has been done by constructing of an MVP, to prove that the open source softwareand commercial hardware can be used to build an autonomousUAV. / Målet med denna kandidatuppsats har varit att evaluera och testa öppen källkod tillsammans med kommersiell hårdvara för att potentiellt kunna nyttjas som elektriskt system i ALPHA UAV. ALPHA UAV är ett studentprojekt, med målet att bygga en autonom drönare kapabel att genomföra höghöjdsflygningar med lång uthållighet för att kunna samla in data från elektromagnetiska fenomen i atmosfären. Data som senare kan nyttjas i forskningssyfte på institutionen för rymd-och plasmafysik på KTH. Evalueringen har gjorts genom att konstruera en MVP, för att bevsia att öppen källkod och kommersiell hårdvara kan nyttjas för att bygga en autonom UAV. / Kandidatexjobb i elektroteknik 2022, KTH, Stockholm

Unmanned Aerial Systems (UAS) are aircraft without a human pilot on board. They are comprised of a ground-based autonomous or human operated control system, an unmanned aerial vehicle (UAV) and a communication, command and control (C3) link between the two systems. UAS are widely used in military warfare, wildfire mapping, aerial photography, etc primarily to collect and process large amounts of data. While they are highly efficient in data collection and processing, they are susceptible to software espionage and data manipulation. This research aims to provide a novel solution to enhance the security of the flight controller thereby contributing to a secure and robust UAS. The proposed solution begins by introducing a new technology in the domain of flight controllers and how it can be leveraged to overcome the limitations of current flight controllers. The idea is to decouple the applications running on the flight controller from the task of data validation. The authenticity of all external data processed by the flight controller can be checked without any additional overheads on the flight controller, allowing it to focus on more important tasks. To achieve this, we introduce an adjacent controller whose sole purpose is to verify the integrity of the sensor data. The controller is designed using minimal resources from the reconfigurable logic of an FPGA. The secondary I/O processor is implemented on an incipient Zynq SoC based flight controller. The soft-core microprocessor running on the configurable logic of the FPGA serves as a first level check on the sensor data coming into the flight controller thereby forming a trusted boundary layer. / Master of Science