To see the other types of publications on this topic, follow the link: Unmanned Aerial Vehicle (UAV).
Dissertations / Theses on the topic 'Unmanned Aerial Vehicle (UAV)'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Unmanned Aerial Vehicle (UAV).'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Allegretti, Marcello. "Unmanned Aerial Vehicle: tecnologie e prospettive future." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/11979/.
Full textAbstract:
Partendo dalla definizione di UAV e UAS, arrivando a quella di drone, nella tesi saranno definiti i termini precedenti, ossia un sistema aereo senza pilota a bordo, la nascita del termine drone e le tendenze attuali. Dopo una precisa classificazione nelle quattro categorie principali (droni per hobbisti, commerciali e militari di me- dia grandezza, militari specifici di grandi dimensioni e stealth da combattimento) saranno descritti gli ambiti di utilizzo: da un lato quello militare e della sicurezza, dall’altro quello civile e scientifico. I capitoli centrali della tesi saranno il cuore dell’opera: l’architettura dell’UAV sarà descritta analizzando la totalità delle sue componenti, sia hardware che software. Verranno, quindi, analizzati i problemi relativi alla sicurezza, focalizzandosi sull’hacking di un UAV, illustrandone le varie tecniche e contromisure (tra cui anche come nascondersi da un drone). Il lavoro della tesi prosegue nei capitoli successivi con un’attenta trattazione della normativa vigente e dell’etica dei droni (nonché del diritto ad uccidere con tali sistemi). Il
capitolo relativo alla tecnologia stealth sarà importante per capire le modalità di occultamento, le tendenze attuali e i possibili sviluppi futuri degli UAV militari da combattimento. Il capitolo finale sugli sviluppi futuri esporrà le migliorie tecnologiche e gli obiettivi degli UAV negli anni a venire, insieme ad eventuali utilizzi
sia militari che civili. La ricerca sarà orientata verso sistemi miniaturizzati, multiple UAV e swarming.
2
Guerra, Elia. "Unmanned Aerial Vehicle (UAV) per applicazioni geomatiche." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016.
Find full textAbstract:
La tesi tratta i dispositivi UAV, in particolare i droni di peso inferiore ai 25 kg, facendo riferimento alla normativa ENAC. Vengono descritte le applicazioni pratiche in campo civile, concentrandosi sulle geomatiche, delineando i principali sensori esterni utilizzati come Camere digitali, termiche e multispettrali.
3
Wagner, Anthony Julian. "Online Unmanned Ground Vehicle Mission Planning using Active Aerial Vehicle Exploration." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/90785.
Full textAbstract:
This work presents a framework for the exploration and path planning for a collaborative
UAV and UGV system. The system is composed of a UAV with a stereo system for obstacle
detection and a UGV with no sensors for obstacle detection. Two exploration algorithms
were developed to guide the exploration of the UAV. Both identify frontiers for exploration
with the Dijkstra Frontier method using Dijkstra's Algorithm to identify a frontier with
unknown space, and the other uses a bi-directional RRT to identify multiple frontiers for
selection. The final algorithm developed was for to give the UGV partial plans when an entire
plan is not yet found. This improves the overall mission tempo. The algorithm is designed
to keep the UGV a safe distance from the unknown frontier to prevent backtracking. All the
algorithms were tested in Gazebo using the ROS framework. The Dijkstra Frontier method
was also tested on the hardware system. The results show the RRT Explore algorithm to
work well for exploring the environment, performing equally or better than the Dijkstra
Frontier method. The UGV partial plan method showed a decreased traveled distance for
the UGV but increases in UGV mission time with more conservative distances from danger.
Overall, the framework showed a good exploration of the environment and performs the
intended missions.Master of Science
This work presents a framework for the exploration and path planning for a collaborative aerial and ground vehicle robotic system. The system is composed of an aircraft with a camera system for obstacle detection and a ground vehicle with no sensors for obstacle detection. Two exploration algorithms were developed to guide the exploration of the aircraft. Both identify frontiers for exploration with the Dijkstra Frontier method using path planning algorithms to identify a frontier with unknown space (Dijkstra Frontier), and the other uses a sampling based path planning method (RRT Explore) to identify multiple frontiers for selection. The final algorithm developed was for to give the ground vehicle intermediate plans when an entire plan is not yet found. The algorithm is designed to keep the ground vehicle a safe distance from the unknown frontier to prevent backtracking. All the algorithms were tested in a simulation framework using Robot Operating System and one exploration method was tested on the hardware system. The results show the RRT Explore algorithm to work well for exploring the environment, performing equally or better than the Dijkstra Frontier method. The ground vehicle intermediate plan method showed a decreased traveled distance for the ground vehicle but increases in ground vehicle mission time with more conservative distances from danger. Overall, the framework showed a good exploration of the environment and performs the intended missions.
4
Kersop, Stefanus Jacobus. "Short range reconnaissance unmanned aerial vehicle / S.J. Kersop." Thesis, North-West University, 2009. http://hdl.handle.net/10394/9171.
Full textAbstract:
Unmanned aerial vehicles (UAVs) have been used increasingly over the past few years. Special Forces of various countries utilise these systems successfully in war zones such as Afghanistan. The biggest advantage is rapid information gathering without endangering human lives.
The South African National Defence Force (SANDF) also identified the need for local short range aerial reconnaissance and information gathering. A detailed literature survey identified various international players involved in the development of small hand-launch UAV systems. Unfortunately, these overseas systems are too expensive for the SANDF. A new system had to be developed locally to comply with the unique requirements, and budget, of the SANDF.
The survey of existing systems provided valuable input to the detailed user requirement statement (URS) for the new South African development. The next step was to build a prototype using off-the-shelf components. Although this aircraft flew and produced good video images, it turned out to be unreliable.
The prototype UAV was then replaced with a standard type model aircraft, purchased from Micropilot. Some modifications were needed to ensure better compliance with the URS. Laboratory and field tests proved that the aircraft can be applied for aerial images, within range of 10 km from the ground control station (GCS). The major limitation is that it can only fly for 40 minutes. Furthermore, the airframe is not robust, needing repairs after only 15 flights.
Although the system has shortcomings, it has already been used successfully. It is expected that improved battery technologies and sturdier light-weight materials will further help to improve the system beyond user specifications.Thesis (MIng (Electrical Engineering))--North-West University, Potchefstroom Campus, 2010.
5
Toazza, Denny Antonio, and Tae Hyun Kim. "Navigation Control of an Unmanned Aerial Vehicle (UAV)." Thesis, Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-3730.
Full textAbstract:
The thesis covers a new navigation algorithm for UAV to fly through several given GPS coordinates without any human interference. The UAV first gets its current position from GPS receiver via Bluetooth connection with the navigator computer. With this GPS point, it draws an optimal trajectory to next destination. During the flight, the navigator computer issues the information about which direction to turn and how much to turn. This information will be used to steer the airplane servos.
The algorithm is programmed in Java LeJOS. It uses built-in Java classes about GPS and Bluetooth. The main computer, where the navigation program runs, is a LEGO Mindstorms NXT and it is used a GPSlim240 from HOLUX as a GPS receiver.
6
Tell, Fredrik. "CCUAV : Cloud Center for Unmanned Aerial Vehicle." Thesis, Högskolan i Halmstad, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-36304.
Full textAbstract:
Projektets syfte är att bryta kopplingen mellan en specifik användare och drönare. Målet med projektet är att flera användare ska kunna hantera flera drönare från en central. En länk mellan en internetbaserad plattform vid namn Thingworx och en drönare med en inbyggd styrenhet, som kallas Pixhawk, sammankopplas med mikrodatorn Raspberry Pi 3. Sjöräddningssällskapet i Sverige önskar ett interface där flera av deras drönare med den inbyggda styrenheten kan hanteras och se dess position och videoström. PDSVisions mål är att skapa en demonstrator i en nyutvecklad plattform som förenklar uppkoppling med enheter med hjälp av ett begrepp som kallas IoT (Internet of Things). Resultat har resulterat i en prototyp av Sjöräddningssällskapets drönare ämnad att kontrolleras via den internetbaserade plattformen Thingworx. Drönaren startar, lyfter från marken och flyger en planerad rutt utan pilot. Slutsatsen visade att projektet kunde genomföras samt att det är möjligt att kommunicera med drönare via Thingworx
7
Meyer, Danielle L. "Energy Optimization of a Hybrid Unmanned Aerial Vehicle (UAV)." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1523493111005807.
Full text
8
Lee, Kyuho. "Development of unmanned aerial vehicle (UAV) for wildlife surveillance." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0008979.
Full text
9
DeJong, Paul. "COALITION FORMATION IN MULTI-AGENT UAV SYSTEMS." Master's thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2712.
Full textAbstract:
Coalitions are collections of agents that join together to solve a common problem that either cannot be solved individually or can be solved more efficiently as a group. Each individual agent has capabilities that can benefit the group when working together as a coalition. Typically, individual capabilities are joined together in an additive way when forming a coalition. This work will introduce a new operator that is used when combining capabilities, and suggest that the behavior of the operator is contextual, depending on the nature of the capability itself. This work considers six different capabilities of Unmanned Air Vehicles (UAV) and determines the nature of the new operator in the context of each capability as coalitions (squadrons) of UAVs are formed. Coalitions are formed using three different search algorithms, both with and without heuristics: Depth-First, Depth-First Iterative Deepening, and Genetic Algorithm (GA). The effectiveness of each algorithm is evaluated. Multi agent-based UAV simulation software was developed and used to test the ideas presented. In addition to coalition formation, the software aims to address additional multi-agent issues such as agent identity, mutability, and communication as applied to UAV systems, in a realistic simulated environment. Social potential fields provide a means of modeling a clustering attractive force at the same time as a collision-avoiding repulsive force, and are used by the simulation to maintain aircraft position relative to other UAVs.M.S.Cp.E.
Department of Electrical and Computer Engineering
Engineering and Computer Science
Computer Engineering
10
Bradley, Justin, and Breton Prall. "AN UNMANNED AERIAL VEHICLE PROJECT FOR UNDERGRADUATES." International Foundation for Telemetering, 2006. http://hdl.handle.net/10150/604143.
Full textAbstract:
ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, CaliforniaBrigham Young University recently introduced a project for undergraduates in which a miniature unmanned aerial vehicle system is constructed. The system is capable of autonomous flight, takeoff, landing, and navigation through a planned path. In addition, through the use of video and telemetry collected by the vehicle, accurate geolocation of specified targets is performed. This paper outlines our approach and successes in facilitating this accomplishment at the undergraduate level.
11
Kim, Yŏng-nae. "Small unmanned aerial vehicle (S-UAV) study for civilian applications." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/47405.
Full text
12
Mize, Lloyd B. IV. "Development of a Multiple Vehicle Collaborative Unmanned Aerial System." VCU Scholars Compass, 2011. http://scholarscompass.vcu.edu/etd/2527.
Full textAbstract:
The purpose of this research was to design a multiple UAV system with collaborative operation. This project is built on work that has been done in the field of Unmanned Systems at VCU and is aimed at providing a starting point for research into collaborative control of multiple UAVs. The current GCS software was extended to include multiple vehicles per single controller via a new communication protocol. Many changes were made to the user interface to facilitate controlling multiple vehicles with a single operator. A second processor, called an MCS, was added to each vehicle to allow for greater flexibility and processing power, while maintaining backwards-compatibility and limiting infringement on the real-time processing of the FCS itself. The system was fully simulated via both hardware and software simulators, and ultimately the system was field tested using multiple vehicles collaboratively searching a defined area.
13
Dowd, Garrett E. "Improving Autonomous Vehicle Safety using Communicationsand Unmanned Aerial Vehicles." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1574861007798385.
Full text
14
Heath, Garrett D. "Simulation analysis of Unmanned Aerial Vehicles (UAV)." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1999. http://handle.dtic.mil/100.2/ADA368265.
Full text
15
Scott, Kevon K. "Occlusion-Aware Sensing and Coverage in Unmanned Aerial Vehicle (UAV) Networks." University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1479816954496473.
Full text
16
Rydalch, Fletcher D. "Missile demonstrator for counter UAV applications." Thesis, Monterey, California. Naval Postgraduate School, 2016. http://hdl.handle.net/10945/55204.
Full textAbstract:
Approved for public release; distribution is unlimited.An autonomously guided rocket-powered delivery vehicle has been under development at the Naval Postgraduate School. Designed to eventually counter UAV swarm attacks, the vehicle made advances toward reaching a target in the sky. These advances reduced the time needed to launch, modify, and relaunch the rocket, while adding capabilities such as data transfer along the vehicle axis and the rapid download of flight data. Improving the vehicle included reconfiguring the guidance, navigation, and control (GNC) strategy. Advancements included the design, implementation, and evaluation of electronic servo control, actuating fins, and the mechanical coupling design. The forward compartment in the vehicle’s nose cone was structurally modified for the GNC equipment and to support electronics under high-g launch conditions. Modifications included innovative designs for managing heat transfer requirements. Using off-the-shelf subsystem components kept the advancements fiscally mindful. After implementing the design features, two final test launches were performed: one demonstrated a control spin rate of 8.5 rad/sec; the other showed the vehicle’s ability to execute pitch maneuvers on a single axis. The test results can be used to improve the GNC software and servo control parameters. Continued development will allow the system to become a viable option for countering UAV swarms.
Ensign, United States Navy
17
Åkesson, Elsa, Maximilian Kempe, Oskar Nordlander, and Rosa Sandén. "Unmanned Aerial Vehicle Powered by Hybrid Propulsion System." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-277115.
Full textAbstract:
I samband med den globala uppvärmningen ökar efterfrågan för rena och förnybara bränslen alltmer i dagens samhälle. Eftersom flygindustrin idag är ansvarig för samma mängd växthusgaser som all motortrafik i Sverige, skulle ett byte till en avgasfri energikälla för flygfarkoster vara ett stort framsteg. Därför har projektet genom modellering framtagit ett hybridsystem av ett batteri och en bränslecell och undersökt hur kombinationen av olika storlekar på dem presterar i en driftcykel. Då batterier har hög specifik effekt men är tunga, kompletteras de med fördel av bränsleceller, som är lättviktiga och bidrar med uthållig strömförsörjning. På så sätt blir hybriden optimal för flygfarkoster. Kandidatarbetet är en del av projektet Green Raven, ett tvärvetenskapligt samarbete mellan instutitionerna Tillämpad Elektrokemi, Mekatronik och Teknisk Mekanik på Kungliga Tekniska Högskolan. Driftcykelmodelleringen gjordes i Simulink, och flera antaganden gjordes beträffande effektprofilen, samt bränslecellens mätvärden och effekt. Tre olika energihushållningsscheman skapades, vilka bestämde bränslecellseffekten beroende på vätgasnivån och batteriets laddningstillstånd. Skillnaden på systemen var vilka intervall av laddningstillstånd hos batteriet som genererade olika effekt hos bränslecellen. Det bästa alternativet visade sig vara 0/100-systemet, eftersom det var det enda som inte orsakede någon degradering av bränslecellens kapacitet.In today’s society, with several environmental challenges such as global warming, the demand for cleanand renewable fuels is ever increasing. Since the aviation industry in Sweden is responsible for the sameamount of greenhouse gas emissions as the motor traffic, a change to a non-polluting energy source forflying vehicles would be considerable progress. Therefore, this project has designed a hybrid system of abattery and a fuel cell and investigated how different combinations of battery and fuel cell sizes perform ina drive cycle, through computer modelling. As batteries possess a high specific power but are heavy, thefuel cells with high specific energy complement them with a sustained and lightweight power supply,which makes the hybrid perfect for aviation. The bachelor thesis is a part of Project Green Raven, aninterdisciplinary collaboration with the institutions of Applied Electrochemistry, Mechatronics andEngineering Mechanics at KTH Royal Institute of Techology. The drive cycle simulations were done inSimulink, and several assumptions regarding the power profile, fuel cell measurements and power weremade. Three different energy management strategies were set up, determining the fuel cell powerdepending on hydrogen availability and state of charge of the battery. The strategies were called 35/65,20/80 and 0/100, and the difference between them was at which state of charge intervals the fuel cellchanged its power output. The best strategy proved to be 0/100, since it was the only option which causedno degradation of the fuel cell whatsoever.
18
Duberg, Daniel. "Safe Navigation of a Tele-operated Unmanned Aerial Vehicle." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-221701.
Full textAbstract:
Unmanned Aerial Vehicles (UAVs) can navigate in indoor environments and through environments that are hazardous or hard to reach for humans. This makes them suitable for use in search and rescue missions and by emergency response and law enforcement to increase situational awareness. However, even for an experienced UAV tele-operator controlling the UAV in these situations without colliding into obstacles is a demanding and difficult task. This thesis presents a human-UAV interface along with a collision avoidance method, both optimized for a human tele-operator. The objective is to simplify the task of navigating a UAV in indoor environments. Evaluation of the system is done by testing it against a number of use cases and a user study. The results of this thesis is a collision avoidance method that is successful in protecting the UAV from obstacles while at the same time acknowledges the operator’s intentions.Obemannad luftfarkoster (UAV:er) kan navigera i inomhusmiljöer och genom miljöer som är farliga eller svåra att nå för människor. Detta gör dem lämpliga för användning i sök- och räddningsuppdrag och av akutmottagning och rättsväsende genom ökad situationsmedvetenhet. Dock är det även för en erfaren UAV-teleoperatör krävande och svårt att kontrollera en UAV i dessa situationer utan att kollidera med hinder. Denna avhandling presenterar ett människa-UAV-gränssnitt tillsammans med en kollisionsundvikande metod, båda optimerade för en mänsklig teleoperatör. Målet är att förenkla uppgiften att navigera en UAV i inomhusmiljöer. Utvärdering av systemet görs genom att testa det mot ett antal användningsfall och en användarstudie. Resultatet av denna avhandling är en kollisionsundvikande metod som lyckas skydda UAV från hinder och samtidigt tar hänsyn till operatörens avsikter.
19
Hogue, Jonathon D. "Mapping a Forest: Utilizing an Unmanned Aerial Vehicle to Track Phenology." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou152353290087685.
Full text
20
Sakarya, Arzu. "Multidisciplinary Design Of An Unmanned Aerial Vehicle Wing." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613606/index.pdf.
Full textAbstract:
In this thesis, the structural design, structural analysis and producibility analysis of an unmanned aerial vehicle wing were performed. Three different wing models, made of different materials, were designed. The wings were aluminum wing model and composite wing modelsmade of prepreg and wet lay-up. All wings have the same aerodynamic geometry and structural configuration under the same flight conditions. The structural designs of three wings were done by using Unigraphics NX. The finite element modeling of the wings were built by using MSC Patran package program. After the application of the loads on models, structural analyses were performed by MSC Nastran. Finally, the producibility analysis of prepreg wing model was conducted by using FiberSIM package program. The prepreg wing model was selected as optimum design with studies conducted in the study considering weight, producibility, cruise and gust stress and displacement conditions.
21
Oncu, Mehmet, and Suleyman Yildiz. "An analysis of human causal factors in Unmanned Aerial Vehicle (UAV) accidents." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/44637.
Full textAbstract:
Approved for public release; distribution is unlimitedHuman error has been identified as the major contributor in many severe aviation mishaps, even for accidents involving Unmanned Aircraft (UA) systems. The Department of Defense (DOD) has used the Human Factors Analysis and Classification System (HFACS) taxonomy successfully for ten years to discover the human error in UA mishaps. It is important not to ignore the indisputable human presence in UA and the possible human-related causal factors in UA mishaps so we might be better able to reduce and prevent possible incidents. HFACS with its four main and 19 subcategories is a useful framework for identifying which factors have arisen historically, and which of them should have priority. The results of this study reveals that among 287 causal factors attributed to 68 accidents, 65 percent of the factors were associated with humans. Moreover, this study also discloses that the rater who categorizes the factors can differently observe, understand, and interpret the findings of mishap investigation; thus, human error may even impact the categorization phase due to the rater’s perception. The research concluded that even though HFACS carried out its functionality well, further study is needed to conduct intense statistical analysis with unlimited data and to validate HFACS with more case studies and various raters.
22
Bagheri, Shahriar. "Modeling, Simulation and Control System Design for Civil Unmanned Aerial Vehicle (UAV)." Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-96458.
Full textAbstract:
Unmanned aerial systems have been widely used for variety of civilian applications over the past few years. Some of these applications require accurate guidance and control. Consequently, Unmanned Aerial Vehicle (UAV) guidance and control attracted many researchers in both control theory and aerospace engineering. Flying wings, as a particular type of UAV, are considered to have one of the most efficient aerodynamic structures. It is however difficult to design robust controller for such systems. This is due to the fact that flying wings are highly sensitive to control inputs. The focus of this thesis is on modeling and control design for a UAV system. The platform understudy is a flying wing developed by SmartPlanes Co. located in Skellefteå, Sweden. This UAV is particularly used for topological mapping and aerial photography. The novel approach suggested in this thesis is to use two controllers in sequence. More precisely, Linear Quadratic Regulator (LQR) is suggested to provide robust stability, and Proportional, Integral, Derivative (PID) controller is suggested to provide reference signal regulation. The idea behind this approach is that with LQR in the loop, the system becomes more stable and less sensitive to control signals. Thus, PID controller has an easier task to do, and is only used to provide the required transient response. The closed-loop system containing the developed controller and a UAV non-linear dynamic model was simulated in Simulink. Simulated controller was then tested for stability and robustness with respect to some parametric uncertainty. Obtained results revealed that the LQR successfully managed to provide robust stability, and PID provided reference signal regulation.
23
Leighton, Joshua (Joshua C. ). "System design of an unmanned aerial vehicle (UAV) for marine environmental sensing." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/79161.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2013.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 68-70).
Technological improvements over the past decade have led to the widespread use of autonomous surface and underwater vehicles for data collection in marine environmental sensing and modeling in coastal environments. However, these vehicles and their sensors still have limitations, especially when tasked with observing highly dynamic or transient processes. We investigate the application of a small unmanned aerial vehicle (UAV) to the study of two such phenomena: Harmful Algal Blooms (HABs) and thermal plumes. A complete field-operable system was developed to identify and characterize HAB events through a human-monitored supervisory control system. This capability was extended with an infrared imaging camera for remote sensing of thermal plumes, enabling future work to augment the in-situ measurements of surface craft with thermal imagery from a UAV. Experiments in Singapore have led to the successful identification and subsequent study of algal blooms on multiple occasions and demonstrated the potential for observation and modeling of thermal plumes.
by Joshua Leighton.
S.M.
24
Masango, Thubalakhe Patrick. "Condition monitoring of a wing structure for an unmanned aerial vehicle (UAV)." Thesis, Cape Peninsula University of Technology, 2015. http://hdl.handle.net/20.500.11838/2384.
Full textAbstract:
Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2015.Currently non-destructive testing techniques for composite aircraft structures are disadvantaged when compared to online Structural Health Monitoring (SHM) systems that monitor the structure while in-service and give real time data. The present research work looks at developing a protocol for online structural health monitoring of a UAV wing structure using PVDF film sensors, especially including the monitoring of structural changes caused by defects. Different types of SHM techniques were studied in relation to carbon fibre composites. Laminate composite make-up and manufacturing process was investigated and vacuum infusion process was used to manufacture the samples that resemble the Guardian II wing structure, then the three-point bending test was used to determine the material properties. Digital Shearography was employed as a stationery non-destructive technique to determine the sensor to structure attachment, type and position of defects that affect the state of performance. Finite Element Analysis (FEA) was done using ANSYS Workbench which served as a modelling tool using a drawing imported from Solid-works. Experimental investigation was done using PVDF sensor embedded on the surface of the sample in a cantilever setup and a vertical Vernier scale to measure the deflection due to impact and vibration loading. A Fluke-View oscilloscope was used as a data logger when the measurement of the output voltage and the natural frequency were recorded. The techniques of using FEA and experimental investigation were then compared. The findings of this study showed that the PVDF sensor is suitable for condition monitoring of a UAV wing structure.
25
FLINT, MATTHEW D. "COOPERATIVE UNMANNED AERIAL VEHICLE (UAV) SEARCH IN DYNAMIC ENVIRONMENTS USING STOCHASTIC METHODS." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1105553725.
Full text
26
Östman, Christian, and Anna Forsberg. "Support System for Landing with an Autonomous Unmanned Aerial Vehicle." Thesis, Linköping University, Linköping University, Linköping University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-16278.
Full textAbstract:
There are a number of ongoing projects developing autonomous vehicles, both helicopters and airplanes. The purpose of this thesis is to study a concept for calculating the height and attitude of a helicopter. The system will be active during landing. This thesis includes building an experimental setup and to develop algorithms and software.
The basic idea is to illuminate the ground with a certain pattern and in our case we used laser pointers to create this pattern. The ground is then filmed and the images are processed to extract the pattern. This provides us with information about the height and attitude of the helicopter. Furthermore, the concept implies that no equipment on the ground is needed. With further development the sensor should be able to calculate the movement of the underlying surface relative to the helicopter. This is very important when landing on a moving surface, e.g. a ship at sea.
To study the concept empirically an experimental setup was constructed. The setup provides us with the necessary information to evaluate how well the system could perform in reality. The setup is built with simple and cheap materials. In the setup an ordinary web camera and laser pointers that are avaliable for everyone have been used.
Det finns flera pågående projekt inom autonomflygande farkoster, både för helikoptrar och flygplan. Syftet med vårt examensarbetet är att undersöka ett koncept för en landningssensor för autonom landning med helikopter. Examensarbetet innebär att bygga en fysisk modell för test av konceptet samt att utveckla mjukvara.
Konceptet för sensorn består av att belysa marken med ett speciellt mönster, i vårt fall skapas mönstret av laserpekare, som därefter fotograferas och bildbehandlas. Detta mönster ger sedan information om helikopterns höjd och attityd i luften. Vidare innebär konceptet också att ingen markutrustning krävs för att sensorn ska fungera. I förlängningen ska man med detta koncept kunna beräkna hur underlaget rör sig relativt helikoptern, vilket är väldigt viktigt vid landning på objekt som rör sig, till exempel ett fartyg.
För att undersöka hur bra sensorn presterar i verkligheten så har en rigg byggts. Riggen är byggd med enkla och billiga material. I det här fallet används en webbkamera och laserpekare som går att köpa i vanliga elektronikaffärer.
27
Owen, Mark Andrew. "Aerial Rendezvous Between an Unmanned Air Vehicle and an Orbiting Target Vehicle." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2881.
Full textAbstract:
In this thesis we develop methods that facilitate an aerial rendezvous between two air vehicles. The objective of this research is to produce a method that can be used to insert a miniature air vehicle behind a rendezvous vehicle and then track that vehicle to enable a visual rendezvous. For this research we assume the rendezvous vehicle is following a relatively stable and roughly elliptical orbit. Path planners and controllers have been developed that can be used to effectively intercept the rendezvous vehicle by inserting the MAV onto the orbit of interest. A method for planning and following time-optimal Dubins airplane interception paths between a miniature air vehicle and the rendezvous vehicle is presented. We demonstrate how a vector field path following a scheme can be used for navigation along these time-optimal Dubins airplane paths. A post-orbit insertion tracking method is also presented which can be used to track the target vehicle on an arbitrarily oriented elliptical orbit while maintaining a specified following distance. We also present controllers that can be used for disturbance rejection during the orbit-insertion and interception operations. All of these methods were implemented in simulation and with hardware. Results from these implementations are presented and analyzed.
28
Simpson, Andrew David. "DEVELOPMENT OF AN UNMANNED AERIAL VEHICLE FOR LOW-COST REMOTE SENSING AND AERIAL PHOTOGRAPHY." UKnowledge, 2003. http://uknowledge.uky.edu/gradschool_theses/191.
Full textAbstract:
The paper describes major features of an unmanned aerial vehicle, designed undersafety and performance requirements for missions of aerial photography and remotesensing in precision agriculture. Unmanned aerial vehicles have vast potential asobservation and data gathering platforms for a wide variety of applications. The goalof the project was to develop a small, low cost, electrically powered, unmanned aerialvehicle designed in conjunction with a payload of imaging equipment to obtainremote sensing images of agricultural fields. The results indicate that this conceptwas feasible in obtaining high quality aerial images.
29
Foster, Tyler Michael. "Dynamic Stability and Handling Qualities of Small Unmanned-Aerial-Vehicles UNMANNED-AERIAL-VEHICLES." BYU ScholarsArchive, 2004. https://scholarsarchive.byu.edu/etd/219.
Full textAbstract:
General aircraft dynamic stability theory was used to predict the natural frequencies, damping ratios and time constants of the dynamic modes for three specific small UAVs with wingspans on the scale from 0.6 meters to 1.2 meters. Using USAF DatCom methods, a spreadsheet program for predicting the dynamic stability and handling qualities of small UAVs was created for use in the design stage of new small UAV concept development. This program was verified by inputting data for a Cessna-182, and by then comparing the program output with that of a similar program developed by DAR Corporation. Predictions with acceptable errors were made for all of the dynamic modes except for the spiral mode. The design tool was also used to verify and develop dynamic stability and handling qualities design guidelines for small UAV designers. Using this design tool, it was observed that small UAVs tend to exhibit higher natural frequencies of oscillation for all of the dynamic modes. Comparing the program outputs with military handling qualities specifications, the small UAVs at standard configurations fell outside the range of acceptable handling qualities for short-period mode natural frequency, even though multiple test pilots rated the flying qualities as acceptable. Using dynamic scaling methods to adjust the current military standards for the short period mode, a new scale was proposed specifically for small UAVs. This scale was verified by conducting flight tests of three small UAVs at various configurations until poor handling qualities were observed. These transitions were observed to occur at approximately the boundary predicted by the new, adjusted scale.
30
Sabo, Chelsea M. S. "Routing and Allocation of Unmanned Aerial Vehicles with Communication Considerations." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1352992466.
Full text
31
Hager, Daniel Michael. "Situational Awareness of a Ground Robot From an Unmanned Aerial Vehicle." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/32825.
Full textAbstract:
In the operation of unmanned vehicles, safety is a primary concern. This thesis focuses on the use of computer vision in the development of a situational awareness system that allows for safe deployment and operation of a ground robot from an unmanned aerial vehicle (UAV). A method for detecting utility cables in 3D range images is presented. This technique finds areas of an image that represent edges in 3D space, and uses the Hough transform to find those edges that take the shape of lines, indicating potential utility cables. A mission plan for stereo image capture is laid out as well for overcoming some weaknesses of the stereo vision system; this helps ensure that all utility cables in a scene are detected. In addition, the system partitions the point cloud into best-fit planes and uses these planes to locate areas of the scene that are traversable by a ground robot. Each planeâ s slope is tested against an acceptable value for negotiation by the robot, and the drop-off between the plane and its neighbors is examined as well. With the results of this analysis, the system locates the largest traversable region of the terrain using concepts from graph theory. The system displays this region to the human operator with the drop-offs between planes clearly indicated. The position of the robot is also simulated in this system, and real-time feedback regarding dangerous moves is issued to the operator.
After a ground robot is deployed to the chosen site, the system must be capable of tracking it in real time as well. To this end, a software routine that uses ARToolkitâ s marker tracking capabilities is developed. This application computes the distance to the robot, as well as the horizontal distance from camera to the robot; this allows the flight controller to issue the proper commands to keep the robot centered underneath the UAV.Master of Science
32
Samuelsson, Mikael. "Evaluation of Stability and Flying Qualities of a Light Unmanned Aerial Vehicle (UAV)." Thesis, KTH, Flygdynamik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-102078.
Full textAbstract:
The objective of this study was to evaluate the ying qualities of a light unmanned aerial vehicle (UAV) developed by the Thai company AVIA Satcom Co., Ltd. Based on the study changes in design was to be suggested to meet stability requirements and recommendations from European Aviation Safety was based on two dierent analyses. First, the stability characteristics in terms of stability modes were examined by creating a flight dynamics model of the studied airplane. Secondly the controllability of the vehicle was investigated by examining the control surfaces. It was found that the original design of the UAV was dynamically unstable and that the control surfaces were too large making the airplane di-cult to y in trim condition. By studying the stability characteristics of the simulated airplane it could be concluded that the UAV was dynamically stable for the improved design and thereby meet the requirements and recommendations.
33
Basson, Willem Albertus. "Fault tolerant adaptive control of an unmanned aerial vehicle." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/17898.
Full textAbstract:
Thesis (MScEng)--Stellenbosch University, 2011.ENGLISH ABSTRACT: This thesis presents the development of an adaptive longitudinal control system for an unmanned aerial vehicle (UAV). The project forms part of a research effort at Stellenbosch University into different fault-tolerant control techniques for UAVs. In order to demonstrate the usefulness of fault-tolerant adaptive control, the control system was designed to handle damage-induced longitudinal shifts in the centre of gravity (CG) of the aircraft, which are known to have a dramatic effect on the stability of a fixed-wing aircraft. Using a simplified force and moment model, equations were derived which model the effect of longitudinal CG shifts on the behaviour of the aircraft. A linear analysis of the longitudinal dynamics using these equations showed that the short period mode can become unstable for backward CG shifts. An adaptive pitch rate controller with the model reference adaptive control structure was designed to re-stabilise the short period mode when the CG shifts backwards. The adaptive law was designed using Lyapunov stability theory. Airspeed, climb rate and altitude controllers were designed around the pitch rate controller to allow full autonomous control of the longitudinal dynamics of the UAV. These outer loops were designed with constant parameters, since they would be unaffected by CG shifts if the adaptive pitch rate controller performed as desired. Pure software simulations as well as hardware-in-the-loop simulations showed that the adaptive control system is able to handle instantaneous shifts in the centre of gravity which would destabilise a fixed-gain control system. These simulation results were validated in flight tests, where the aircraft was destabilised using positive feedback and re-stabilised by the adaptive control system. Thus the simulation and flight test results showed that an adaptive control can re-stabilise an unstable aircraft without explicit knowledge of the change in the aircraft dynamics, and therefore could be effective as part of an integrated fault-tolerant control system.
AFRIKAANSE OPSOMMING: Hierdie tesis bied die ontwikkeling aan van ’n aanpassende longitudinale beheerstelsel vir ’n onbemande vliegtuig. Die projek is deel van navorsing by die Universiteit van Stellenbosch oor verskillende fout-tolerante beheertegnieke vir onbemande vliegtuie. Om die doeltreffendheid van aanpassende beheer te demonstreer, is die beheerstelsel ontwerp om situasies te kan hanteer waar die vliegtuig só beskadig word dat sy massamiddelpunt agtertoe skuif, wat ’n groot invloed op die stabiliteit van ’n vastevlerk-vliegtuig kan hê. ’n Vereenvoudigde model van die kragte en momente wat op die vliegtuig inwerk is gebruik om vergelykings af te lei wat beskryf hoe die gedrag van die vliegtuig verander as die massamiddelpunt agtertoe verskuif. Hierdie vergelykings is gebruik in ’n lineêre analise van die longitudinale dinamika van die vliegtuig, wat getoon het dat die kortperiode-modus onstabiel kan raak as die massamiddelpunt agtertoe verskuif. ’n Aanpassende heitempobeheerder met die modelverwysings-aanpassende beheerstruktuur is ontwerp om die kortperiode-modus weer te stabiliseer wanneer die massamiddelpunt agtertoe verskuif. Die aanpassingswet is ontwerp deur die gebruik van Lyapunov se stabiliteitsteorie. Lugspoed-, klimtempo- en hoogtebeheerders is rondom die aanpassende heitempobeheerder ontwerp sodat die longitudinale dinamika van die vliegtuig heeltemal outonoom beheer kan word. Hierdie buitelusse is ontwerp met vaste parameters, aangesien hulle nie geraak sal word deur verskuiwings in die massamiddelpunt as die aanpassende heitempobeheerder na wense werk nie. Suiwer sagteware-simulasies, sowel as hardeware-in-die-lus-simulasies, het getoon dat die aanpassende beheerstelsel oombliklike verskuiwings in die massamiddelpunt goed kan hanteer, waar sulke verskuiwings ’n beheerstelsel met vaste parameters onstabiel sou maak. Hierdie simulasie-resultate is bevestig deur vlugtoetse te doen, waar die vliegtuig onstabiel gemaak is deur positiewe terugvoer, en weer deur die aanpassende beheerstelsel stabiel gemaak is. Die simulasie- en vlugtoetsresultate wys dus dat aanpassende beheer ’n onstabiele vliegtuig weer kan stabiliseer sonder eksplisiete kennis van die veranderinge in die dinamika van die vliegtuig. Aanpassende beheer kan dus doeltreffend wees as deel van ’n geïntegreerde fout-tolerante beheerstelsel.
34
Di, Long. "Cognitive Formation Flight in Multi-Unmanned Aerial Vehicle-Based Personal Remote Sensing Systems." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/985.
Full textAbstract:
This work introduces a design and implementation of using multiple unmanned aerial vehicles (UAVs) to achieve cooperative formation flight based on the personal remote sensing platforms developed by the author and the colleagues in the Center for Self-Organizing and Intelligent Systems (CSOIS). The main research objective is to simulate the multiple UAV system, design a multi-agent controller to achieve simulated formation flight with formation reconfiguration and real-time controller tuning functions, implement the control system on actual UAV platforms and demonstrate the control strategy and various formation scenarios in practical flight tests. Research combines analysis on flight control stabilities, develop- ment of a low-cost UAV testbed, mission planning and trajectory tracking, multiple sensor fusion research for UAV attitude estimations, low-cost inertial measurement unit (IMU) evaluation studies, AggieAir remote sensing platform and fail-safe feature development, al- titude controller design for vertical take-off and landing (VTOL) aircraft, and calibration and implementation of an air pressure sensor for wind profiling purposes on the developed multi-UAV platform. Definitions of the research topics and the plans are also addressed.
35
Alkeryd, Martin. "Evaluation of Position Sensing Techniques for an Unmanned Aerial Vehicle." Thesis, Linköping University, Department of Electrical Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6298.
Full textAbstract:
The use of Unmanned Aerial Vehicles (UAVs) has rapidly increased over the last years. This has been possible mainly due to the increased computing power of microcontrollers and computers. An UAV can be used in both civilian and military areas, for example surveillance and intelligence. The UAV concerned in this master's thesis is a prototype and is currently being developed at DST Control AB in Linköping.
With the use of UAVs, the need for a positioning and navigation system arises. Inertial sensors can often give a good position estimation, however, they need continuous calibration due to error build-up and drift in gyros. An external reference is needed to correct for this drift and other errors. The positioning system investigated in this master's thesis is supposed to work in an area defined by an inverted cone with the height of 25m and a diameter of 10m.
A comparison of different techniques suitable for position sensing has been performed. These techniques include the following: a radio method based on the Instrument Landing System (ILS), an optical method using a Position Sensing Detector (PSD), an optical method using the Indoor GPS system, a distance measurement method with ultrasound and also a discussion of the Global Positioning System (GPS).
An evaluation system has been built using the PSD sensor and tests have been performed to evaluate its possibilities for positioning. Accuracy in the order of a few millimetres has been achieved in position estimation with the evaluation system.
36
Edwards, Barrett Bruce. "An Onboard Vision System for Unmanned Aerial Vehicle Guidance." BYU ScholarsArchive, 2010. https://scholarsarchive.byu.edu/etd/2381.
Full textAbstract:
The viability of small Unmanned Aerial Vehicles (UAVs) as a stable platform for specific application use has been significantly advanced in recent years. Initial focus of lightweight UAV development was to create a craft capable of stable and controllable flight. This is largely a solved problem. Currently, the field has progressed to the point that unmanned aircraft can be carried in a backpack, launched by hand, weigh only a few pounds and be capable of navigating through unrestricted airspace. The most basic use of a UAV is to visually observe the environment and use that information to influence decision making. Previous attempts at using visual information to control a small UAV used an off-board approach where the video stream from an onboard camera was transmitted down to a ground station for processing and decision making. These attempts achieved limited results as the two-way transmission time introduced unacceptable amounts of latency into time-sensitive control algorithms. Onboard image processing offers a low-latency solution that will avoid the negative effects of two-way communication to a ground station. The first part of this thesis will show that onboard visual processing is capable of meeting the real-time control demands of an autonomous vehicle, which will also include the evaluation of potential onboard computing platforms. FPGA-based image processing will be shown to be the ideal technology for lightweight unmanned aircraft. The second part of this thesis will focus on the exact onboard vision system implementation for two proof-of-concept applications. The first application describes the use of machine vision algorithms to locate and track a target landing site for a UAV. GPS guidance was insufficient for this task. A vision system was utilized to localize the target site during approach and provide course correction updates to the UAV. The second application describes a feature detection and tracking sub-system that can be used in higher level application algorithms.
37
Elmagri, Loay Hatem Rajab. "Architecture and Drones: Accomodating Unmanned Aerial Vehicles." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/87584.
Full textAbstract:
Through out history, technological advancements have reshaped the built environment and its Architecture. The cities that we live in today were only made possible by the technologies of the first, second, and third industrial revolutions. Today, we are witnessing another technological revolution based on open source data and artificial intelligence.
As there is an enormous amount of prosperous innovations that would directly impact Architecture design tools, building and finishing materials, and construction methods, there are also other innovations that would require spaces, buildings, and cities to be designed to accommodate them. Among the latter mentioned innovations is the Unmanned Aerial Vehicle (UAV), also know as drones.
Like the automobile, drone technology will influence not only the way we live but also our design thinking and the components of our built environment. Along with drone�s ability to fly, UAV�s digital infrastructure is much more flexible and most importantly, invisible. Autonomous Drones� intelligent abilities allow them to provide a wide range of services in various fields such as; freight and delivery, transportation, infrastructure and buildings maintenance, survey, surveillance, policing, fire fighting, agriculture, and even construction, all of which will effectively reduce the amount of ground vehicle traffic, especially in populated cities. Today, as these possibilities are available and constantly under development, it is important for Architecture and Urban Design disciplines to address the challenge and provide comprehensive solutions to accommodate such a technology and allow its possibilities to prosper even further.
The intent of this thesis is to study UAV technology and design a mix-use complex that embraces and accommodates UAV services such as; delivery, transport, freight, and maintenance. The complex hosts a residential tower, a vertical garden tower, ground level commercial spaces, and an underground drone hub.MArch
38
Sjöberg, Mattias. "Analysis of autonomous flight algorithms for an unmanned aerial vehicle." Thesis, Umeå universitet, Institutionen för fysik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-147625.
Full textAbstract:
Unmanned Aerial Vehicles (UAV) have been heavily studied in the past decade, where autonomous flights have been a popular subject. More complex applications have led to higher requirements on the autonomous flight algorithms and the absence of performance data complicates the selection of what algorithm to use for various applications. Therefore, this thesis focused in analyzing the performance difference between two methods, Simultaneous Localization AndMapping (SLAM) and Artificial Potential Field Approach (APFA), which are planning and reactive algorithms, respectively. Fundamental dynamics were applied, Feedback Linear Controllers (FBLC)s for stabilization and an odometry position model combined with an inverse dynamics technique that linearizes the non-linear odometry model. The SLAM approach was set up in four steps: landmark extraction which uses a point distance based method for segment separation, combined with a Split-And-Merge algorithm for extracting linear landmarks, data association that validates the landmarks, Extended Kalman Filter (EKF) that uses the landmarks together with the odometry model for estimating the position of the UAV, and a modified TangentBug as the reactive algorithm. The APFA was constructed of two functions, an attractive and a repulsive function. The two methods were implemented on the robotics simulation platform Virtual Robot Experimentation Platform (V-REP), where a quadcopter was used as the model for the UAV. All theory was implemented onto the quadcopter model and embedded scripts were used for communication within V-REP, mainly through internal Application Programming Interface (API)-functions. Furthermore, a script was written that randomly generates three different types of simulation environments. The implementation of both methods was analyzed in reaching an arbitrary goal position in terms of: the most successful, the most time efficient and the safest navigation path. Another thing analyzed was the time- and space-complexity of both implemented methods. The results stated that the implemented APFA and the SLAM approach had approximately equal success rate, SLAM had the safest navigation, was the most time efficient, and had the highest time- and space-complexity for a worst case scenario. One of the conclusions were that improvements could be done in the implementations. Future work includes adding a proper damping method, improving the flaws in the implemented methods as well as to use V-REP as a Robot Operating System (ROS)-node for creating a Software In The Loop (SITL)-simulation, in order to achieve more realistic simulations.
39
Hayes, Edwin Laurie. "Machine Learning for Intelligent Control: Application of Reinforcement Learning Techniques to the Development of Flight Control Systems for Miniature UAV Rotorcraft." Thesis, University of Canterbury. Department of Mechanical Engineering, 2013. http://hdl.handle.net/10092/7810.
Full textAbstract:
This thesis investigates the possibility of using reinforcement learning (RL) techniques to create a flight controller for a quadrotor Micro Aerial Vehicle (MAV).
A capable flight control system is a core requirement of any unmanned aerial vehicle. The challenging and diverse applications in which MAVs are destined to be used, mean that considerable time and effort need to be put into designing and commissioning suitable flight controllers. It is proposed that reinforcement learning, a subset of machine learning, could be used to address some of the practical difficulties.
While much research has delved into RL in unmanned aerial vehicle applications, this work has tended to ignore low level motion control, or been concerned only in off-line learning regimes. This thesis addresses an area in which accessible information is scarce: the performance of RL
when used for on-policy motion control.
Trying out a candidate algorithm on a real MAV is a simple but expensive proposition. In place of such an approach, this research details the development of a suitable simulator environment, in which a prototype controller might be evaluated. Then inquiry then proposes a possible RL-based control system, utilising the Q-learning algorithm, with an adaptive RBF-network providing function approximation.
The operation of this prototypical control system is then tested in detail, to determine both the absolute level of performance which can be expected, and the effect which tuning critical parameters of the algorithm has on the functioning of the controller. Performance is compared against a conventional PID controller to maximise the usability of the results by a wide audience. Testing considers behaviour in the presence of disturbances, and run-time changes in plant dynamics.
Results show that given sufficient learning opportunity, a RL-based control system performs as well as a simple PID controller. However, unstable behaviour during learning is an issue for future analysis.
Additionally, preliminary testing is performed to evaluate the feasibility of implementing RL algorithms in an embedded computing environment, as a general requirement for a MAV flight controller. Whilst the algorithm runs successfully in an embedded context, observation reveals
further development would be necessary to reduce computation time to a level where a controller was able to update sufficiently quickly for a real-time motion control application.
In summary, the study provides a critical assessment of the feasibility of using RL algorithms for motion control tasks, such as MAV flight control. Advantages which merit interest are exposed, though practical considerations suggest at this stage, that such a control system is not a realistic proposition. There is a discussion of avenues which may uncover possibilities to surmount these challenges. This investigation will prove useful for engineers interested in the opportunities which reinforcement learning techniques represent.
40
Straub, Benjamin Preston. "Instrumentation and Control of a Ducted Fan Unmanned Aerial Vehicle in Hover Mode." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/72889.
Full textAbstract:
Unmanned aerial vehicles (UAVs) are increasingly being used for both military and commercial applications to replace more costly and dangerous manned operations. Vehicles with vertical take-off and landing (VTOL) and hovering capabilities are of interest for functions such as surveillance and inspection where the ability to hold the position of the vehicle is desired. Ducted fan vehicles are of particular interest because of their high efficiency per unit diameter when compared to the more commonly seen multirotor vehicles. This makes ducted fan UAVs very well suited for size-constrained missions such as indoor inspection or urban reconnaissance. However, the advantages of ducted fans come at the cost of complex nonlinear dynamics which present challenging modeling and control problems.
This thesis provides a detailed discussion of the instrumentation, modeling, and control of a ducted fan UAV. The dynamic model of the UAV is computed from a simplified parametric model. Unknown parameters of the model are found from system identification based on flight data. Synthesis of a linear state feedback controller based on this model is discussed, and it is demonstrated in hardware that this controller can effectively stabilize the vehicle.Master of Science
41
Noonan, Andrea L. "Flight plan generation for unmanned aerial vehicles." Thesis, Manhattan, Kan. : Kansas State University, 2007. http://hdl.handle.net/2097/385.
Full text
42
Mylin, Alicia K. "A COMMUNICATION LINK RELIABILITY STUDY FOR SMALL UNMANNED AERIAL VEHICLES." UKnowledge, 2007. http://uknowledge.uky.edu/gradschool_theses/483.
Full textAbstract:
Dependable communication links for unmanned aerial vehicles (UAV) are crucial to operational reliability and mission success. This study is focused on evaluating the probability of successful communication links for small UAVs. A program based on the Friis Transmission Equation was developed to calculate the power received in a line-of-sight communication link. The program was used to evaluate the probability of success for a variety of flight pa
43
Blaney, Sean. "Unmanned aerial vehicle-based non-destructive testing methods for concrete structures." Thesis, Elsevier; Cement and Concrete Composites, 2018. https://dspace.library.uvic.ca//handle/1828/9757.
Full textAbstract:
In this work, unmanned aerial vehicle-based non-destructive testing methods for concrete structures are evaluated and developed. There exists a need for improved infrastructure inspection techniques with increased expediency. Unmanned aerial vehicles (UAVs) are highly mobile and have shown promise towards achieving this directive, but more work is required to adapt traditional NDT methods to be UAV-compatible. To this end, concrete sounding techniques were evaluated with a quantitative acoustic frequency analysis procedure on a series of concrete slabs. One such method was adapted for use with a UAV and was used to detect subsurface voids in one of the concrete samples and offer a means of depth estimation. This work was complemented with experiments concerning UAV-based visual and infrared imaging techniques already in practice for UAV-based concrete inspection. Together, findings indicate the strengths and weaknesses of the NDTs tested and suggest further improvements for UAV-based NDTs and inspection strategies moving forward. Development of a novel sensor platform for UAV-based measurement, as well as results of an actual bridge inspection using infrared and optical methods demonstrate the present capabilities of the UAV-based instrumentation.Graduate
2019-07-03
44
Larsen, Thor Liland. "Unmanned Aerial Vehicles for Post Disaster Surveys." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/429.
Full textAbstract:
In the current built environment, structures require regular observation and maintenance. Many of these structures can be quite challenging to evaluate. The required scaffolding, lifts, or similar access facilities can become quite costly to rent and construct, and can be a long term disturbance to those who use and manage the particular structure. Furthermore, there are situations where examination for the purpose of detailed analysis can be quite hazardous, if not entirely unsafe for humans. In a post-disaster environment traditional methods may not be safe or adequate for gaining access to parts of a structure that require observation or analysis. The use of a remotely controlled unmanned vehicle is a reliable, safe and cost effective substitute for assessing structures before and after seismic, terrorist, or other destructive events.
45
Alberts, Frederik Nicolaas. "Accurate autonomous landing of a fixed-wing unmanned aerial vehicle." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71672.
Full textAbstract:
Thesis (MScEng)-- Stellenbosch University, 2012.ENGLISH ABSTRACT: This thesis presents the analysis, design, simulation and practical implementation of a control system to achieve an accurate autonomous landing of a fixed-wing unmanned aerial vehicle in the presence of wind gust atmospheric disturbances. Controllers which incorporate the concept of direct-lift control were designed based on a study of the longitudinal dynamics of the UAV constructed as a testbed. Direct-lift control offers the prospect of an improvement in the precision with which aircraft height and vertical velocity can be controlled by utilising actuators which generate lift directly, instead of the conventional method whereby the moment produced by an actuator results in lift being indirectly generated. Two normal specific acceleration controllers were designed. The first being a conventional moment-based controller, and the second a direct-lift-augmented controller. The moment-based controller makes use of the aircraft’s elevator while the direct-lift augmented controller in addition makes use of the flaps of the aircraft which serve as the direct-lift actuator. Controllers were also designed to regulate the airspeed, altitude, climb rate, and roll angle of the aircraft as well as damp the Dutch roll mode. A guidance controller was implemented to allow for the following of waypoints. A landing procedure and methodology was developed which includes the circuit and landing approach paths and the concept of a glide path offset to calibrate the touchdown point of a landing. All controllers and the landing procedure were tested in a hardware-in-the-loop simulation environment as well as practically in a series of flight tests. Five fully autonomous landings were performed, three of these using the conventional NSA controller, and the final two the direct-lift-augmented NSA controller. The results obtained during the landing flight tests show that the project goal of a landing within five meters along the runway and three meters across the runway was achieved in both normal wind conditions as well as in conditions where wind gusts prevailed. The flight tests also showed that the direct-lift-augmented NSA controller appears to achieve a more accurate landing than the conventional NSA controller, especially in the presence of greater wind disturbances. The direct-lift augmented NSA controller also exhibited less pitch angle rotation during landing.
AFRIKAANSE OPSOMMING: Hierdie tesis verteenwoordig die analise, ontwerp, simulasie en praktiese implementering van ’n beheerstelsel wat ten doel het om ’n akkurate en outonome landing van ’n onbemande vastevlerk vliegtuig in rukwind atmosferiese toestande te bewerkstellig. Gegrond op ’n studie van die longitudinale dinamika van die vliegtuig wat as proeftuig gebruik is, is beheerders ontwerp wat die beginsel van direkte-lig insluit. Direkte-lig beheer hou die potensiaal in om die vliegtuig se hoogte en vertikale snelheid akkuraat te beheer deur gebruik te maak van aktueerders wat lig direk genereer in teenstelling met die konvensionele metode waar die moment van die aktueerder indirek lig genereer. Twee normaal-versnellings beheerders is ontwerp. Die eerste is ’n konvensionele moment-gebaseerde beheerder wat gebruik maak van die hys-aktueerder van die vliegtuig, en die tweede is ’n direkte-lig-bygestaande beheerder wat addisioneel gebruik maak van die flappe van die vliegtuig wat as die direkte-lig aktueerder dien. Vedere beheerders is ontwerp wat die lugspoed, hoogte, klimkoers, en rolhoek van die vliegtuig reguleer asook die “Dutch roll” gedrag afklam. ’n Leiding-beheerder wat die volg van vliegbakens hanteer, is ingestel. Die landingsprosedure en -metodologie is ontwikkel wat die landingspad sowel as die sweef-pad bepaal en wat terselfdertyd ’n metode daarstel om die posisie van die landingspunt te kalibreer. Die beheerders en landingsprosedure is in ’n hardeware-in-die-lus omgewing gesimuleer en deur middel van ’n reeks proefvlugte getoets. Vyf ten volle outonome landings is uitgevoer waarvan drie van die konvensionele normaal-versnellings beheerder gebruik gemaak het, en die laaste twee die direkte-lig-bygestaande normaal-versnellings beheerder. Die vlugtoetsuitslae bevestig dat die navorsingsdoel om ’n landing binne vyf meter in lyn met en drie meter dwarsoor die landingstrook te bewerkstellig, behaal is. Hierdie akkuraatheid is verkry in beide goeie atmosferiese toestande sowel as toestande met rukwinde. Volgens die vlugtoetse blyk dit dat die direkte-lig-bygestaande normaalversnellings beheerder ’n meer akkurate landing kan bewerkstellig as die konvensionele normaal-versnellings beheerder, veral dan in toestande met rukwinde. Die direkte-ligbygestaande normaal-versnellings beheerder het ook ’n laer hei-hoek rotasie tydens die landing vertoon.
46
Gurtner, Alex. "Investigation of fisheye lenses for small UAV aerial photography." Thesis, Queensland University of Technology, 2008. https://eprints.qut.edu.au/19323/1/Alex_Gurtner_Final_Thesis.pdf.
Full textAbstract:
Aerial photography obtained by UAVs (Unmanned Aerial Vehicles) is an emerging market for civil applications. Small UAVs are believed to close gaps in niche markets, such as acquiring airborne image data for remote sensing purposes. Small UAVs will be able to fly at low altitudes, in dangerous environments and over long periods of time. However, the small lightweight constructions of these UAVs lead to new problems, such as higher agility leading to more susceptibility to turbulence and limitations in space and payload for sensor systems. This research investigates the use of low-cost fisheye lenses to overcome such problems which theoretically makes the airborne imaging less sensitive to turbulence. The fisheye lens has the benet of a large observation area (large field of view) and doesn't add additional weight to the aircraft, like traditional mechanical stabilizing systems. This research presents the implementation of a fisheye lens for aerial photography and mapping purposes, including theoretical background of fisheye lenses. Based on the unique feature of the distortion being a function of the viewing angle, methods used to derive the fisheye lens distortion are presented. The lens distortion is used to rectify the fisheye images before these images can be used in aerial photography. A detailed investigation into the inner orientation of the camera and inertial sensor is given, as well as the registration of airborne collected images. It was found that the attitude estimation is critical towards accurate mapping using low quality sensors. A loosely coupled EKF filter applied to the GPS and inertial sensor data estimated the attitude to an accuracy of 3-5° (1-sigma) using low-cost sensors typically found in small UAVs. However, the use of image stitching techniques may improve the outcome. On the other hand, lens distortion caused by the fisheye lens can be addressed by rectification techniques and removed to a sub-pixel level. Results of the process present image sequences gathered from a piloted aircraft demonstrating the achieved performance and potential applications towards UAVs. Further, an unforeseen issue with a vibrating part in the lens lead to the need for vibration compensation. The vibration could be estimated to ±1 pixel in 75% of the cases by applying an extended Hough transform to the fisheye images.
47
Gurtner, Alex. "Investigation of fisheye lenses for small UAV aerial photography." Queensland University of Technology, 2008. http://eprints.qut.edu.au/19323/.
Full textAbstract:
Aerial photography obtained by UAVs (Unmanned Aerial Vehicles) is an emerging market for civil applications. Small UAVs are believed to close gaps in niche markets, such as acquiring airborne image data for remote sensing purposes. Small UAVs will be able to fly at low altitudes, in dangerous environments and over long periods of time. However, the small lightweight constructions of these UAVs lead to new problems, such as higher agility leading to more susceptibility to turbulence and limitations in space and payload for sensor systems. This research investigates the use of low-cost fisheye lenses to overcome such problems which theoretically makes the airborne imaging less sensitive to turbulence. The fisheye lens has the benet of a large observation area (large field of view) and doesn't add additional weight to the aircraft, like traditional mechanical stabilizing systems. This research presents the implementation of a fisheye lens for aerial photography and mapping purposes, including theoretical background of fisheye lenses. Based on the unique feature of the distortion being a function of the viewing angle, methods used to derive the fisheye lens distortion are presented. The lens distortion is used to rectify the fisheye images before these images can be used in aerial photography. A detailed investigation into the inner orientation of the camera and inertial sensor is given, as well as the registration of airborne collected images. It was found that the attitude estimation is critical towards accurate mapping using low quality sensors. A loosely coupled EKF filter applied to the GPS and inertial sensor data estimated the attitude to an accuracy of 3-5° (1-sigma) using low-cost sensors typically found in small UAVs. However, the use of image stitching techniques may improve the outcome. On the other hand, lens distortion caused by the fisheye lens can be addressed by rectification techniques and removed to a sub-pixel level. Results of the process present image sequences gathered from a piloted aircraft demonstrating the achieved performance and potential applications towards UAVs. Further, an unforeseen issue with a vibrating part in the lens lead to the need for vibration compensation. The vibration could be estimated to ±1 pixel in 75% of the cases by applying an extended Hough transform to the fisheye images.
48
Tan, Ruoyu. "Tracking of Ground Mobile Targets by Quadrotor Unmanned Aerial Vehicles." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1378194694.
Full text
49
Hogge, Jeffrey V. "Development of a Miniature VTOL Tail-Sitter Unmanned Aerial Vehicle." Diss., CLICK HERE for online access, 2008. http://contentdm.lib.byu.edu/ETD/image/etd2372.pdf.
Full text
50
Fan, Jiankun. "Optimal Path Planning and Control of Quadrotor Unmanned Aerial Vehicle for Area Coverage." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1417345596.
Full text