This dissertation aims to apply non-zero attitude and position setpoint tracking to a quadrotor aircraft, achieved by solving the problem of a quadrotor’s inherent underactuation. The introduction of extra actuation aims to mechanically accommodate for stable tracking of non-zero state trajectories. The requirement of the project is to design, model, simulate and control a novel quadrotor platform which can articulate all six degrees of rotational and translational freedom (6-DOF) by redirecting and vectoring each propeller’s individually produced thrust. Considering the extended articulation, the proposal is to add an additional two axes (degrees) of actuation to each propeller on a traditional quadrotor frame. Each lift propeller can be independently pitched or rolled relative to the body frame. Such an adaptation, to what is an otherwise well understood aircraft, produces an over-actuated control problem. Being first and foremost a control engineering project, the focus of this work is plant model identification and control solution of the proposed aircraft design. A higher-level setpoint tracking control loop designs a generalized plant input (net forces and torques) to act on the vehicle. An allocation rule then distributes that virtual input in solving for explicit actuator servo positions and rotational propeller speeds. The dissertation is structured as follows: First a schedule of relevant existing works is reviewed in Ch:1 following an introduction to the project. Thereafter the prototype’s design is detailed in Ch:2, however only the final outcome of the design stage is presented. Following that, kinematics associated with generalized rigid body motion are derived in Ch:3 and subsequently expanded to incorporate any aerodynamic and multibody nonlinearities which may arise as a result of the aircraft’s configuration (changes). Higher-level state tracking control design is applied in Ch:4 whilst lower-level control allocation rules are then proposed in Ch:5. Next, a comprehensive simulation is constructed in Ch:6, based on the plant dynamics derived in order to test and compare the proposed controller techniques. Finally a conclusion on the design(s) proposed and results achieved is presented in Ch:7. Throughout the research, physical tests and simulations are used to corroborate proposed models or theorems. It was decided to omit flight tests of the platform due to time constraints, those aspects of the project remain open to further investigation. The subsequent embedded systems design stemming from the proposed control plant is outlined in the latter of Ch:2, Sec:2.4. Such implementations are not investigated here but design proposals are suggested. The primary outcome of the investigation is ascertaining the practicality and feasibility of such a design, most importantly whether or not the complexity of the mechanical design is an acceptable compromise for the additional degrees of control actuation introduced. Control derivations and the prototype design presented here are by no means optimal nor the most exhaustive solutions, focus is placed on the whole system and not just a single aspect of it.

Consumer drones have used both standards such as Wi-Fi as well as proprietary communication protocols, such as DJI's OcuSync. While these methods are well suited to certain flying scenarios, they are limited in range to around 4.3 miles. Government and military unmanned aerial vehicles (UAVs) controlled through satellites allow for a global reach in a low-latency environment. To address the range issue of commercial UAVs, this thesis investigates using standardized cellular technologies for command and control of UAV systems. The thesis is divided into five chapters: Chapter 1 is the introduction to the thesis. Chapter 2 describes the equipment used as well as the test setup. This includes the drone used, the cellular module used, the microcontroller used, and a description of the software written to collect the data. Chapter 3 describes the data collection goals, as well as locations in the sky that were flown in order to gather experimental data. Finally, the results are presented in Chapter 4, which draws limited correlation between the collected data and flight readiness Chapter 5 wraps up the thesis with a conclusion and future areas for research are also presented.

Lighter than air (LTA) vehicles have many advantageous capabilities over other aircraft, including low power consumption, high payload capacity, and long endurance. However, they exhibit manoeuvrability and control reliability challenges, and these limitations are particularly significant for smaller unmanned LTA. In this thesis, a 4 m length autonomous airship with a sliding gondola is presented. A rigid keel, mounted to the helium envelope, follows the helium envelope profile from the midsection to the nose of the vehicle. Moving the gondola along the keel produces upwards of 90-degree changes in pitch angle, thereby improving manoeuvrability and allowing for rapid changes in altitude. The longitudinal multi-body equations of motion were developed for this prototype using the Boltzmann–Hamel method. An adaptive PID controller was then designed to control the pitch inclination using the gondola’s position. This control system is capable of self-tuning the controller gains in real time by minimizing a pre-defined sliding condition. Experimental flight tests were carried out to evaluate the controller’s performance on the prototype.

Electrically powered vertical takeoff and landing (eVTOL) aircraft could provide a new mode of air transportation of people and cargo that is low-cost, on-demand, and able to reach more areas than is possible with current technology. They have the unique ability to takeoff and land in congested spaces yet efficiently travel long distances which makes them a promising technology for applications such as rapid medical assistance, automated package delivery, or human transportation. This type of aircraft has only recently become a possibility, owing to advancements in battery technology, computing power, and sensor technologies, and thus support for eVTOLs is lacking among high-fidelity graphics simulation software. High-fidelity graphics are important for the goal of fully autonomous eVTOL aircraft in order to accurately simulate vision-based navigation using camera sensors. In this work, we present VTOL-AirSim, an extension of Microsoft AirSim with full integration of a tiltrotor eVTOL aircraft. Built on Unreal Engine, a high-end graphics game engine, it includes photorealistic graphics for simulated camera images and for high-quality presentations. We created the visual components of a fully animated tiltrotor vehicle and a detailed city environment for it to fly in. The tiltrotor can be controlled via motor PWM commands, by overriding its state in the world with the use of an external dynamics simulation, or by using the PX4 Autopilot. We give a tutorial on how to use VTOL-AirSim where we provide examples for each method of control, including scripts for controlling the tiltrotor via a geometric controller and control allocation module developed by others in the BYU MAGICC Lab. We also show how to further develop VTOL-AirSim, and how to add custom aircraft or custom environments so that others may use it in their own research.

Military unmanned aerial vehicles (UAVs) perform missions in airspace where one of the mission goals may be radar-detection avoidance. The research conducted aimed at determining optimum flight-path routes that make maximum utilization of UAV terrain masking opportunities and flight range capability in avoiding radar detection. The problem was formulated as one of constrained optimization in three dimensions and advantageous solutions were identified using Algorithm A*. The study conducted extended the substantial existing literature on radar-detection avoidance for UAVs in three significant ways: First, it explicitly modeled prominent terrain cover, such as forests and urban areas, in masking radar detection through the adaptation of a ray-casting technique in order to determine if expanded flight path cells were visible to any nearby radar. Any existing terrain cover masking prospects were exploited by the algorithm to avoid radar detection, in addition to prospects arising for terrain masking through topographical features. Second, it explicitly modeled the trade-off between detection risk and flight-path length by using a weighted average of the total flight-path length and the radar detectable flightpath length as the objective function to be minimized. The relative importance of detection risk and flight-path length is captured by adjusting the weights. Third, a mission planning process was obtained allowing route selection based on the characteristics of a portfolio of parameters and options, including radar detection exposure, the total distance traveled on a respective flight path, and a computed missile shoot-down risk benchmark for each option. The benchmark estimates the likelihood of aircraft destruction from missile impact subsequent to an integrated air defense system detection, acquisition, tracking, and missile launch sequence. The model was further extended to include provisions for preferred altitude ranges, adjustable aircraft climb and descent rate envelopes, fractional detection probability based movement costs (accounting for simultaneous detection by multiple radars), radar horizon masking, and a perspective based ellipsoidal radar cross section model. Resulting routes can be executed at a significantly lower expected cost than the alternative of using a human piloted stealth aircraft that may be required for a similar mission in the absence of intelligent route-planning.

Indiana University-Purdue University Indianapolis (IUPUI) / In 21st century, interoperability in remote locations has always been a matter of contention. Interoperability is very closely related to internet and an efficient process saves a lot of time and money. With the advent of Wireless Sensor Networks (WSN), Native Internet Protocol (NIP) is considered as one of the most pragmatic solutions in market to address interoperability challenges and is gaining more attention in research. However, challenges like reliability, security of data, power consumption, range and maintenance, and accessibility of such internet in remote locations still remain a matter of concern, creating further barriers for interoperability. This research aims at proposing a viable solution to interoperability issues at remote locations, irrespective of its network or payload size, by integrating more advanced Wireless Sensor Protocols like Thread Protocol with a proposed Over The Air (OTA) file transfer functionality, into UAVs. Furthermore, this study analyzes power consumption, reliability, latency and scope of the proposed system and their applications in health care and industries.

No description available.

This paper gives a thοrοugh lοοk in the use οf Unmanned Aerial Vehicles (UAV) in search and rescue missiοns. The οbjective is tο identify, thrοugh a literature review, all types οf UAV, the available remοte sensοrs that can be mοunted in a UAV and what type οf data each sensοr prοvides, the methοdοlοgy οn flight planning and what is the regulatοry framewοrk, guidelines and limitatiοns, οf UAV flight in sοme οf the biggest cοuntries wοrldwide and in specific fοr the Eurοpean Uniοn and Sweden. Alsο, a brief research in the field οf machine learning was dοne in οrder tο identify the pοssibilities given in use οf οbject recοgnitiοn and avοidance techniques. In the case οf Sweden, we have alsο identified the framewοrk fοr the Search and Rescue οperatiοns accοrding tο the “Civil Prοtectiοn Act. Gοvernment Bill 2002/03:119. Refοrmed rescue services legislatiοn”, in whοse hands falls the respοnsibility tο use and implement UAVs in such type οf missiοns. The main οbjectives fοr future develοpment are the full autοnοmy οf a UAV, the energy limitatiοns in the οperatiοnal phase, the fast prοcessing οf data οnbοard and the acquisitiοn οf the data thrοugh cοmmunicatiοn links withοut the need οf a physical cοnnectiοn between the UAV and the grοund cοntrοl statiοn (GCS). Accοrding tο οur research the οptimal cοnfiguratiοn οf UAVs in a search and rescue scenariο is a fleet οf fully autοnοmοus heterοgeneοus UAVs (fixed-wing UAVs and quadcοpters) with sοlar panels attached tο the fixed-wing UAVs, a high-resοlutiοn camera, a thermal camera and a Synthetic Aperture Radar (SAR). As the field οf UAVs is vastly grοwing the research οn the subject was cοnducted until April 1st, 2018 due tο new papers and research cοnducted in the subject regularly.

Syftet med examensarbetet är att undersöka markstödens placeringar och fördelningar i plan och om höjden har en inverkan på noggrannheten i ortomosaik. En jämförelse genomförs mellan totalstation och UAV-koordinater. Först utfördes rekognosering i fält för att sedan placera ut åtta stycken markstödsplattor varpå ett av markstöden blev placerad på en högre höjd. En ytterligare variant av markstödstyp placerades ut i form av ett grönt kryss med sprayflaska. Markstöden och kontrollpunkterna mättes in med totalstation efter fristationsuppställning där tre bakåtobjekt används för att erhålla noggranna plana koordinater. En fixpunkt används för att erhålla stabila höjder.  I denna studie användes en UAV i form av DJI Phantom 4 Pro vid flygfotograferingen och en totalstation (Trimble S7) för inmätningarna. Inmätningen utfördes med totalstation mot kontrollpunkterna med samtliga markstöd som tillämpades sedan som facit. Slutligen utfördes UAV-flygning med en flygrutt på 60 m höjd och 90 graders vinkel för UAVkameran. Bildbearbetningen utfördes i programvaran Agisoft Metashape där fem stycken modeller genererades i form av ortomosaik och DEM. Sedan med hjälp av ortomosaiken exporterades koordinaterna till programvaran Microsoft Excel för vidare bearbetning och kontroll av avvikelser mellan UAV- och totalstationens koordinater. Resultaten från ortomosaikmodellerna visar att RMS i plan och höjd påverkas beroende på antalet markstöd. Modellen utan markstöd resulterar i en stor koordinatdifferens med RMS i plan på cirka 2 m. Vid användning av fyra markstöd ses en markant förbättring i noggrannhet för RMS i plan på cirka 0,008 m och i höjd på 0,045 m. För modellen med fem markstöd påvisas inga märkbara skillnader för RMS i plan, men för RMS i höjd erhålls betydligt lägre mätosäkerhet. Sista modellen med åtta markstöd resulterar i lägst mätosäkerhet i plan och höjd jämfört mot de andra modellerna, men skillnaden var oansenlig mellan fem och åtta markstöd. Utifrån frågeställningen och framtaget resultat kan det fastslås att ortomosaiksmodellen med fem markstöd är lämpligast för vidare användning vid flygfotografering. Markstödsplatta rekommenderas för noggrannare höjdkoordinater jämfört med märkspray. Om endast plana koordinater ska bearbetas kan antingen märkspray eller markstödsplatta utnyttjas för att erhålla likvärdigt resultat. / The objective of the bachelor thesis is to examine if ground control point (GCP) placing and allocation would impact the accuracy of an orthomosaic. A comparison between total station and UAV-coordinates is carried out. Reconnaissance was carried out in the field to deploy the GCP around the study area with one of them deployed on top of a pile. A different variant of GCP is deployed in the form of green-coloured cross that was applied with the help of a spray bottle. Both GCP and control points were measured with total station after the free station set-up where the three backsights and a fixed point were used to obtain a stable height. During the studies, a DJI Phantom 4 Pro UAV was used for aerial photography and a total station (Trimble S7) for the measurements. Before the flight, measurements were calculated with the total station to the control points and all GCP, which were then used as a record. GNSS-drone flying was performed with a flight route at a height of 60 meters and a 90 degrees angle for the UAV camera. Image processing was performed in software Agisoft Metashape where a total five orthomosaic models were generated. Then with the help of orthomosaic, the coordinates were transferred to the software Microsoft Excel for further processing and control of deviation between the coordinates of the UAV and the total station. Results from the orthomosaic models show that RMS in both plane and height do impact accuracy depending on the numbers of GCP used. A model without the use of GCP shows a huge coordinate difference for RMS in plane at approximately two meters. The use of four GCP models show a significant improvement in both RMS in plane at approximately 0,008 meters and the height at 0,046 meters. Five GCP models show a slight difference for RMS in plane but is considerable when the height was at 0,008 meters. Lastly, eight GCP models show some small significant improvements in both RMS plane and height.  Based on the questions and results, it can be stated that the orthomosaic models with five GCP are recommended for further use of drone surveying. The GCP wooden plate is to be preferred for a more accurate height compared to the green cross spray method. But if only planar coordinates are considered, both GCP wooden plate and green cross spray bottle can be used with equal accuracy.

Drones are unmanned aerial vehicles (UAVs) operated remotely with the help of cameras, GPS, and on-device SD cards. These are used for many applications including civilian as well as military. On the other hand, drone swarms are a fleet of drones that work together to achieve a special goal through swarm intelligence approaches. These provide a lot of advantages such as better coverage, accuracy, increased safety, and improved flexibility when compared to a single drone. However, the deployment of such swarms in an adversarial environment poses significant challenges. This work provides an overview of the current state of research on drone swarms in adversarial environments including algorithms for swarming formation of robotic attack drones with their strengths and weaknesses as well as the attack strategies used by attackers. This work also outlines the common adversarial counter-attack methods to disrupt drone attacks consisting of detection and destruction of drone swarms along with their drawbacks, a counter UAV defense system, and splitting large-scale drones into unconnected clusters. After identifying several challenges, an optimized algorithm is proposed to split the large-scale drone swarms more efficiently.