To see the other types of publications on this topic, follow the link: UAV (unmanned aerial vehicles).
Dissertations / Theses on the topic 'UAV (unmanned aerial vehicles)'
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 'UAV (unmanned aerial vehicles).'
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
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
2
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.
3
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
4
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
5
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
6
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.
7
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.
8
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
9
Hasnain, Syed Saad. "Navigation of Unmanned Aerial Vehicles Using Image Processing." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-105628.
Full textAbstract:
The purpose of this thesis is to investigate the possibility of using aerial or satellite images or eventually digital elevation models in order to localize the UAV helicopter in the environment. Matching techniques are investigated in order to match the available on-board image of the area with the live images acquired by the on-board video camera. The problem is interesting because it can provide a redundancy for the UAV navigation system which is based only on GPS. The thesis is in the context of the development of an integrated system for navigation using image sequences from an aircraft. The system is composed of relative position estimation, which computes the current position of the helicopter by accumulating relative displacement extracted from successive aerial images. These successive aerial images are then matched using certain image matching techniques.
10
Howe, William Beaman. "DESIGN METHODS FOR REMOTELY POWERED UNMANNED AERIAL VEHICLES." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1386.
Full textAbstract:
A method for sizing remotely powered unmanned aerial vehicles is presented to augment the conventional design process. This method allows for unconventionally powered aircraft to become options in trade studies during the initial design phase. A design matrix is created that shows where, and if, a remotely powered vehicle fits within the design space. For given range and power requirements, the design matrix uses historical data to determine whether an internal combustion or electrical system would be most appropriate. Trends in the historical data show that the break in the design space between the two systems is around 30 miles and 1 kW. Electrical systems are broken into subcategories of onboard energy sources and remote power sources. For this work, only batteries were considered as an onboard energy source, but both lasers and microwaves were considered for remote power transmission methods. The conventional sizing method is adjusted to so that it is based on energy consumption, instead of fuel consumption. Using the manner in which microwaves and laser propagate through the atmosphere, the weight fraction of a receiving apparatus is estimated. This is then used with the sizing method to determine the gross takeoff weight of the vehicle. This new sizing method is used to compare battery systems, microwave systems, and laser systems.
11
Pinchin, James Thomas. "GNSS Based Attitude Determination for Small Unmanned Aerial Vehicles." Thesis, University of Canterbury. Mechanical Engineering, 2011. http://hdl.handle.net/10092/5759.
Full textAbstract:
This thesis is concerned with determining the orientation of small Unmanned Aerial Vehicles(UAVs). To make commercial use of these aircraft in aerial surveying markets their attitude needs to be determined accurately and precisely throughout a survey flight.
Traditionally inertial sensors have been used on larger aircraft to estimate both position and orientation in combination with Global Navigation Satellite Systems (GNSS). High quality inertial sensors have many downsides when used on the small UAV. They are expensive, power hungry and often heavy. Inertial sensors are vulnerable to vibration, high acceleration, high rotation rate and jerk. All of these are present on the small UAV. This thesis identifies GNSS attitude determination as a potentially suitable alternative to inertial techniques.
Carrier phase GNSS attitude determination uses three or more GNSS receivers with antennas separated by a short baseline to estimate the orientation of the UAV. This technique offers low cost, high accuracy and drift-free attitude estimates. To be successfully used it requires removal of the biases present in the received GNSS signals and estimation of the integer cycle ambiguity present in the carrier phase measurement.
This thesis presents and examines the state of the art techniques for removing these biases and estimating an integer cycle ambiguity using a priori measurement of the interantenna distance. In this work a novel method is developed which uses this a priori baseline measurement to validate estimates of the carrier phase ambiguities.
In order to test these methods data has been gathered using low cost, commercially available GNSS receivers and antennas. This is the first work in which modern, low cost, GNSS equipment has been tested for use in attitude determination. It is found that the state of the art carrier phase GNSS attitude determination methods can provide an accurate attitude estimate for every set of measurements from the GNSS receivers.
However, a real UAV flight indicates that the low cost GNSS equipment does not track the GNSS signals throughout the flight. Signal outages, cycle slips and half cycle ambiguous carrier phase measurements occur due to rapid UAV manoeuvres. Having identified this problem this work goes on to replicate and quantify it through the use of a GNSS hardware simulator. Algorithms are then devised to increase the availability of the GNSS attitude solution throughout the tracking difficulties.
Complete GNSS signal tracking failures are overcome through the innovative use of kinematic and dynamic attitude models. Both types of model give an attitude solution throughout GNSS signal tracking problems without adding significant cost or weight to the system. When tracking of the GNSS carrier phase signal is possible, novel use of the carrier phase triple difference observable allows the attitude rate to be estimated even when the carrier phase measurements are half cycle ambiguous. It is shown that integer and half integer cycle slips can be removed from the measurement through the combination of the modelling and triple difference techniques.
The attitude output of both modelling and triple difference methods is used to resolve half cycle ambiguities and make full use of half cycle ambiguous data where previously it could not have been used. Success rates of up to 99.6% have been achieved for half cycle ambiguity resolution. As a result precise and accurate GNSS attitude solutions are available at nearly every epoch for which a carrier phase measurement is output by the GNSS receivers. When no measurement is available the attitude solution gracefully degrades over time.
This work makes reliable, accurate, low cost attitude determination possible on mini-UAVs.
12
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.
13
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.
14
Deittert, Markus. "The Albatross UAV : propulsion by dynamic soaring for unmanned aerial vehicles." Thesis, University of the West of England, Bristol, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.557598.
Full textAbstract:
Dynamic soaring is an engineless flight technique, which extracts energy from a wind gradient. i.e. a change in wind speed with height. It is the key method by which albatrosses achieve their long endurance flight of several thousand miles, flown with hardly a flap of their wings. Such flying takes the albatross close to the water's surface and usually occurs in strong wind conditions. Development of unmanned aerial vehicles (DAVs) is driven by the need of long endurance flight. Techniques such as increasing the engine's fuel efficiency and increasing the amount of fuel carried on-board, suffer from diminishing returns. To achieve ultra long en- durance flight the limits of on-board energy storage must -be overcome by exploiting a source of ambient environmental energy. This thesis investigates dynamic soaring flight as a means of propulsion for DAVs of about 3 metres wingspan. Trajectory optimisation is the central method of investigation used in this thesis. A faster and more efficient approach is presented in this work. by exploiting the DAV's flight model's differential flatness property. The trajectory optimisation process is used to establish outer bounds on the range of feasible wind speeds. for a generic example DAV. From these outer bounds, the probability of favourable winds is investigated, in six candidate locations in the Antarctic Ocean. the Atlantic Ocean, the North Sea and the English Channel. Our example DAV's flight performance closely matches the albatross' flight performance in its natural habitat, the Antarctic Ocean. However, the achievable likelihood of favourable winds is too low in European waters to justify using dynamic soaring as a primary means of propulsion and it must be used together with other flight techniques and propulsion methods to achieve adequate reliability and robustness. By studying the sensitivity of the minimal and maximal wind conditions to flight path con- straints and physical parameters of the DAV model, further insight is gained into the technique of dynamic soaring. Previous work by other authors concentrated upon finding general tra- jectories, with flight models carefully normalised to reduce the number of parameters to one or two variables which represent the whole aircraft. In this thesis, parameters are considered individually. Key results are identification of the maximum airspeed limit as a key factor for the upper bound on feasible wind speeds and the height of the trajectory's low point above ground as a key factor for overall performance. Establishing outer bounds on the feasible wind speed range naturally raises the question of which range of wind speeds within the outer bounds can be exploited in practice. Wind speeds of sufficient magnitude for dynamic soaring are strongly associated with atmospheric turbulence. Because dynamic soaring trajectories are situated very close to the surface, trajectory errors are a particular concern. The ability of an DAV to fly in turbulent conditions is thus closely related to the ability of its control system to reject external disturbances. The performance of a periodic LQR-based controller is evaluated in simulation with particular care having been placed on the turbulence model. It was found, that stabilising the UAV on the nominal trajectory does not necessarily coincide with good energy management and a future control system design should explicitly address energy extraction and management.
15
Pawlenko, Matthew. "Derivation of river bathymetry using imagery from unmanned aerial vehicles (UAV)." Thesis, Monterey, California. Naval Postgraduate School, 2011. http://hdl.handle.net/10945/5466.
Full textAbstract:
Approved for public release; distribution is unlimited.In many places that U.S. forces operate, there exists an insufficient amount of data regarding river water depths, which is a necessity for safe operational planning. Satellite sensors and airborne manned platforms have been used for bathymetric derivation, but are not in abundance, nor do they have the spatial resolution required to examine smaller rivers. Using Unmanned Aerial Vehicles (UAV), this research examines the feasibility of using a ratio method with digital imagery to derive water depths, as well as a simpler polynomial regression to create a lookup table for use in the field. The results show that the ratio method of Red to Blue had higher correlation than Red color band on its own, and that the simple polynomial regression using a ratio of Red to Blue had higher correlation than more widely accepted methods. However, both methods are limited by a maximum depth, which is defined as the point where color no longer changes with depth. All depths beyond this point appear as this maximum depth. These findings show that using imagery from UAVs for bathymetric derivation could be a feasible alternative to accepted satellite imagery methods, but further research is needed to demonstrate operational utility.
16
Eriksson, Urban. "Dynamic Path Planning for Autonomous Unmanned Aerial Vehicles." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-241243.
Full textAbstract:
This thesis project investigates a method for performing dynamic path planning in three dimensions, targeting the application of autonomous unmanned aerial vehicles (UAVs). Three different path planning algorithms are evaluated, based on the framework of rapidly-exploring random trees (RRTs): the original RRT, RRT*, and a proposed variant called RRT-u, which differs from the two other algorithms by considering dynamic constraints and using piecewise constant accelerations for edges in the planning tree. The path planning is furthermore applied for unexplored environments. In order to select a path when there are unexplored parts between the vehicle and the goal, it is proposed to test paths to the goal location from every vertex in the planning graph to get a preliminary estimate of the total cost for each partial path in the planning tree. The path with the lowest cost given the available information can thus be selected, even though it partly goes through unknown space. For cases when no preliminary paths can be obtained due to obstacles, dynamic resizing of the sampling region is implemented increasing the region from which new nodes are sampled. This method using each of the three different algorithms variants, RRT, RRT*, and RRT-u, is tested for performance and the three variants are compared against each other using several test cases in a realistic simulation environment. KeywordsDetta examensarbete undersöker metoder för att utföra dynamisk ruttplanering i tre dimensioner, med applicering på obemannade luftfarkoster. Tre olika ruttplaneringsalgoritmer testas, vilka är baserade på snabbt-utforskande slumpmässiga träd (RRT): den ursprungliga RRT, RRT*, och en föreslagen variant, RRT-u, vilken skiljer sig från dom två första algoritmerna genom att ta hänsyn till dynamiska begränsningar och använda konstanta accelerationer över delar av rutten. Ruttplaneraren används också i okända miljöer. För att välja en rutt när det finns outforskade delar mellan farkosten och målet föreslås det att testa rutten till målpunkten från varje nod i som ingår i planeringsträdet för att erhålla en preliminär total kostnad till målpunkten. Rutten med lägsta kostanden kan då väljas, givet tillgänglig information, även om den delvis går genom outforskade delar. För tillfällen när inga preliminära rutter kan erhållas på grund av hinder har dynamisk storleksjustering av samplingsområdet implementerats för att öka området från vilket nya noder samplas. Den här metoden har testats med dom tre olika algoritmvarianterna, RRT, RRT*, och RRT-u, och dom tre varianterna jämförs med avseende på prestanda i ett flertal testfall i en realistisk simuleringsmiljö.
17
Christiansen, Reed Siefert. "Design Of An Autopilot For Small Unmanned Aerial Vehicles." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd445.pdf.
Full text
18
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.
19
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.
20
Clarke, Jonathan H. A. "Navigation and autonomy of soaring unmanned aerial vehicles." Thesis, Loughborough University, 2012. https://dspace.lboro.ac.uk/2134/12337.
Full textAbstract:
The use of Unmanned Aerial Vehicles (UAV) has exploded over the last decade with the constant need to reduce costs while maintaining capability. Despite the relentless development of electronics and battery technology there is a sustained need to reduce the size and weight of the on-board systems to free-up payload capacity. One method of reducing the energy storage requirement of UAVs is to utilise naturally occurring sources of energy found in the atmosphere. This thesis explores the use of static and semi-dynamic soaring to extract energy from naturally occurring shallow layer cumulus convection to improve range, endurance and average speed. A simulation model of an X-Models XCalibur electric motor-glider is used in combination with a refined 4D parametric atmospheric model to simulate soaring flight. The parametric atmospheric model builds on previous successful models with refinements to more accurately describe the weather in northern Europe. The implementation of the variation of the MacCready setting is discussed. Methods for generating efficient trajectories are evaluated and recommendations are made regarding implementation. For micro to small UAVs to be able to track the desired trajectories a highly accurate Attitude Heading Reference System (AHRS) is needed. Detailed analysis of the practical implementation of advanced attitude determination is used to enable optimal execution of the trajectories generated. The new attitude determination methods are compared to existing Kalman and complimentary type filters. Analysis shows the methods developed are capable of providing accurate attitude determination with extremely low computational requirements, even during extreme manoeuvring. The new AHRS techniques reduce the need for powerful on-board microprocessors. This new AHRS technique is used as a foundation to develop a robust navigation filter capable of providing improved drift performance, over traditional filters, in the temporary absence of global navigation satellite information. All these algorithms have been verified by flight tests using a mixture of manned and unmanned aerial vehicles and avionics developed specifically for this thesis.
21
Gustafsson, Hanna, and Lea Zuna. "Unmanned Aerial Vehicles for Geographic Data Capture: A Review." Thesis, KTH, Geodesi och satellitpositionering, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210039.
Full textAbstract:
In GIS-projects the data capture is one of the most time consuming processes. Both how to collect the data and the quality of the collected data is of high importance. Common methods for data capture are GPS, LiDAR, Total Station and Aerial Photogrammetry. Unmanned Aerial Vehicles, UAVs, have become more common in recent years and the number of applications continues to increase. As the technique develops there are more ways that UAV technique can be used for collection of geographic data. One of these techniques is the UAV photogrammetry that entails using an UAV equipped with a camera combined with photogrammetric software in order to create three dimensional models and orthophotos of the ground surface. This thesis contains a comparison between different geographic data capture methods such as terrestrial and aerial methods as well as UAV photogrammetry. The aim is to investigate how UAVs are used to collect geographic data today as well how the techniques involving UAVs can replace or be used as a complement to traditional methods. This study is based on a literature study and interviews. The literature study aims to give a deeper insight in where and how UAVs are used today for geographic data capturing with focus on three main areas: environmental monitoring, urban environment and infrastructure, and natural resources. Regarding the interviews companies and other participants using UAVs for geographic data collection in Sweden have been interviewed to get an accurate overview of the current status regarding the use of UAVs in Sweden. Advantages, disadvantages, limitations, economical aspects, accuracy and possible future use or development are considered as well as different areas of applications. The study is done in collaboration with the geographic IT company Digpro Solutions AB. The goal is to be able to present suggestions of how UAV data can be applied in Digpros applications. Information from the literature study and the interviews show that using a UAV makes it possible to cover a large range between terrestrial and aerial methods, and that it can replace or complement other methods for surveying and data collection. The use gives the possibility to get close to the object without being settle to the ground, as well as work environment profits since dangerous, difficult areas can be accessed from distance. The data can be collected faster, quicker, cheaper and more frequent. Time savings occurs in the measurement stage but compared to terrestrial methods more time is required for the post-processing of the data. The use in Sweden is limited due to difficulties linked to Swedish legislation regarding camera surveillance, as well as long waiting times for the permissions that is required to fly. However, a change in the camera surveillance law is expected which means that UAVs will be excluded from the law. That may result in great benefits for everyone within the industry as well as a continued development of the technique and the use of UAVs.Inom GIS ar datainsamling en av de mest tidskrävande processerna. Både hur data samlas in samt kvaliteten ar av hög vikt. Några av de vanligaste metoderna för datainsamling idag är GPS, LiDAR, totalstation och fotogrammetri. Obemannade flygfarkoster, UAVs, har de senaste åren blivit allt vanligare och användningsområdena fortsätter att öka. I takt med att tekniken hela tiden utvecklas finns idag flertalet satt att med hjälp av UAVs samla in geografisk data. Med kamerautrustade obemannade flygfarkoster och fotogrammetriska programvaror ar det bland annat möjligt att skapa tredimensionella modeller samt ortofoton av markytan. Detta kandidatexamensarbete innehaller en jämförelse mellan terrestra- samt flygburna metoder för datainsamling och obemannade flygburna metoder. Syftet är att undersöka hur UAVs kan anvandas för att samla in geografisk data samt möjligheten att ersätta eller komplettera existerande metoder, samt att presentera en overgripande bild av UAVs anvandningsomåden. Denna studie bygger pa en litteraturstudie samt intervjuer. Litteraturstudien syftar till en djupare inblick i anvandningsområden för UAV tekniken med fokus på tre huvudområden: miljöövervakning, urbana miljöer och infrastruktur samt naturliga resurser. Under intervjuerna intervjuades företag och andra aktörer inom branschen med syftet att göra en nulägesanalys av hur UAVs används för insamling av geografisk data i Sverige. Det insamlade materialet analyserades med avseende pa användningsområden, för- och nackdelar, hinder, kostnader, noggrannhet samt möjlig framtida användning och utveckling av tekniken. Studien är gjord i samarbete med företaget Digpro Solutions AB som är verksamma inom geografisk IT. Målet är att efter studien kunna ge förslag på hur data insamlad med UAV kan appliceras på Digpros applikationer. Information fran intervjuerna och litteraturen har visat att UAV täcker ett stort spann mellan terrestra- och flygburna metoder, och att den kan ersätta eller utgöra ett komplement till många mät- och datainsamlingsmetoder. Användningen av UAVs innebär möjlighet till att samla in data på ett nära avstånd till objekt utan att vara bunden till marken. Den medför även arbetsmiljövinster då farliga, svårtillgängliga områden kan nås från avstånd. Data kan samlas in snabbare, enklare, billigare och mer frekvent. Tisdbesparingar sker i inmätningsskedet men jämfört med terrestra mätmetoder krävs dock mer tid för efterbearbetning av mätdatat. Användningen i Sverige begränsas av svårigheter kopplade till Svensk lagstiftning gällande kameraövervakning, samt långa väntetider på de tillstånd som kravs för att få flyga. Dock väntas en ändring i kameraövervakningslagen som innebär att drönare inte innefattas i lagen. Detta kan komma att medföra stora fördelar för samtliga inom branschen samt en fortsatt utveckling av tekniken samt användningen av UAVs.
22
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.
23
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
24
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.
25
Шевченко, Юлія Вікторівна, Yuliya Viktorivna Shevchenko, and Anna Ayrapetyan. "Adaptive method of unmanned aerial vehicles (UAV) driving in an obscure environment." Thesis, National Aviation University, 2020. https://er.nau.edu.ua/handle/NAU/48919.
Full textAbstract:
In our country, despite difficult economic and geopolitical conditions, the development of unmanned aerial vehicles (UAVs) is taking place as part of the development of domestic aviation. All over the world, this area is being actively developed, and it has definitely been supported by domestic researchers. Unmanned systems are being actively developed in the geodesic, agro-industrial and aerospace industries, used in everyday life and have many prospects for their practical application. Researcher`s interest in this area has made it possible to achieve certain results in a short time, but there are still many unresolved issues. One important area of research is the problem of adapting the autonomous UAV to the external environment. The task is much more complicated if the UAV flies at low altitudes above a complex terrain. In other words, the external environment
is unknown or little known and can change dynamically. These are current scientific and practical challenges that need to be addressed. Analysis of recent research and publications.У нашій країні, незважаючи на складні економічні та геополітичні умови, розробка безпілотних літальних апаратів (БПЛА) відбувається як частина розвитку вітчизняної авіації. У всьому світі ця сфера активно розвивається, і це, безумовно, підтримано вітчизняними дослідниками. Безпілотні системи активно розробляються в геодезичній, агропромисловій та аерокосмічній промисловості, використовуються в повсякденному житті і мають багато перспектив для їх практичного застосування. Зацікавленість дослідника в цій галузі дозволила за короткий час досягти певних результатів, але все ще існує багато невирішених питань. Одним із важливих напрямів досліджень є проблема адаптації автономного БПЛА до зовнішнього середовища. Завдання набагато складніше, якщо БПЛА летить на невеликій висоті над складною місцевістю. Іншими словами, зовнішнє середовище невідомий або маловідомий і може динамічно змінюватися. Це поточні наукові та практичні завдання, які потребують вирішення. Аналіз останніх досліджень та публікацій.
26
Rennu, Samantha R. "Dynamic Mission Planning for Unmanned Aerial Vehicles." University of Dayton / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=dayton16082274381124.
Full text
27
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
28
Patibandla, Siva Teja. "Development of Mobile Ad-Hoc Network for Collaborative Unmanned Aerial Vehicles." VCU Scholars Compass, 2013. http://scholarscompass.vcu.edu/etd/3155.
Full textAbstract:
The purpose of this research was to develop a mobile ad-hoc network for collaborative Unmanned Aerial Vehicles (UAVs) based on a mesh networking standard called IEEE 802.11s. A low-cost, small form-factor, IEEE 802.11a based wireless modem was selected and integrated with the existing flight control system developed at Virginia Commonwealth University (VCU) UAV Laboratory. A self-configurable user-space application on the wireless modem was developed to provide functionality to collaborative algorithms, and to monitor the performance of the wireless network. The RAMS simulator, developed at VCU, was upgraded to support the simulation of advanced networking capabilities by integrating with a simulator called ns-3. The reconfigurability and performance of the IEEE 802.11s mesh network was validated and evaluated by conducting real-world flights. The results show that the IEEE 802.11s is a promising solution for collaborative UAV applications.
29
Ostler, Jon N. "Flight Testing Small, Electric Powered Unmanned Aerial Vehicles." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1223.pdf.
Full text
30
Ortiz, Jose. "Development of a Low Cost Autopilot System for Unmanned Aerial Vehicles." VCU Scholars Compass, 2010. http://scholarscompass.vcu.edu/etd/2252.
Full textAbstract:
The purpose of this thesis was to develop a low cost autonomous flight control system for small unmanned aerial vehicles with the aim to support collaborative systems. A low cost hardware solution was achieved by careful selection of sensors, integration of hardware subsystems, and the use of new microcontroller technologies. Flight control algorithms to guide a vehicle though waypoint based flight paths and loiter about a point were implemented using direction fields. A hardware in the loop simulator was developed to ensure proper operation of all hardware and software components prior to flight testing. The resulting flight control system achieved stable and accurate flight while reducing the total system cost to less than $250.
31
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
32
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
33
Klomparens, Dylan. "Automated Landing Site Evaluation for Semi-Autonomous Unmanned Aerial Vehicles." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/34641.
Full textAbstract:
A system is described for identifying obstacle-free landing sites for a vertical-takeoff-and-landing (VTOL) semi-autonomous unmanned aerial vehicle (UAV) from point cloud data obtained from a stereo vision system. The relatively inexpensive, commercially available Bumblebee stereo vision camera was selected for this study. A â point cloud viewerâ computer program was written to analyze point cloud data obtained from 2D images transmitted from the UAV to a remote ground station. The program divides the point cloud data into segments, identifies the best-fit plane through the data for each segment, and performs an independent analysis on each segment to assess the feasibility of landing in that area. The program also rapidly presents the stereo vision information and analysis to the remote mission supervisor who can make quick, reliable decisions about where to safely land the UAV. The features of the program and the methods used to identify suitable landing sites are presented in this thesis. Also presented are the results of a user study that compares the abilities of humans and computer-supported point cloud analysis in certain aspects of landing site assessment. The study demonstrates that the computer-supported evaluation of potential landing sites provides an immense benefit to the UAV supervisor.Master of Science
34
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
35
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
36
Gardner, Michael Alan. "A Feasibility Study of Cellular Communication and Control of Unmanned Aerial Vehicles." Thesis, University of North Texas, 2019. https://digital.library.unt.edu/ark:/67531/metadc1609109/.
Full textAbstract:
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.
37
Basson, Matthys Michaelse. "Stall prevention control of fixed-wing unmanned aerial vehicles." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4310.
Full textAbstract:
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: This thesis presents the development of a stall prevention flight control subsystem, which can easily be integrated into existing flight control architectures of fixed-wing unmanned aerial vehicles (UAV’s). This research forms an important part of faulttolerant flight control systems and will ensure that the aircraft continues to operate safely within its linear aerodynamic region. The focus of this thesis was the stall detection and prevention problem. After a thorough literature study on the topic of stall, a model based stall prevention control algorithm with feedback from an angle of attack sensor was developed. This algorithm takes into account the slew rate and saturation limits of the aircraft’s servos and is able to predict when the current flight condition will result in stall. The primary concern was stall during wings-level flight and involved the prevention of stall by utilising only the elevator control surface. A model predictive slew rate control algorithm was developed to override and dynamically limit the elevator command to ensure that the angle of attack does not exceed a predefined limit. The stall prevention control system was designed to operate as a switching control scheme, to minimise any restrictions imposed on the existing flight control system. Finally, software in the loop simulations were conducted using a nonlinear aircraft model and realistic sensor noise, to verify the theoretical results obtained during the development of this stall prevention control strategy. A worst-case performance analysis was also conducted to investigate the robustness of the control algorithms against model uncertainties.
AFRIKAANSE OPSOMMING: Hierdie tesis handel oor die ontwikkeling van ’n staak voorkomings-vlugbeheer substelsel wat maklik geïntegreer kan word in bestaande vlugbeheer argitektuur van onbemande vaste-vlerk lugvaartuie. Hierdie tesis vorm ’n belangrike deel van fouttolerante vlugbeheertegnieke en sal verseker dat die vliegtuig slegs binne sy lineêre aerodinamiese werksgebied bly. Die fokus van hierdie tesis is die staak opsporing en voorkomings probleem. Na afloop van ’n deeglike literatuurstudie oor die onderwerp van staak, is ’n model gebaseerde staak voorkomings-beheertegniek ontwikkel, wat terugvoer van ’n invalshoek sensor ontvang. Hierdie algoritme neem die sleur tempo en defleksie limiete van die vliegtuig se servos in ag en is in staat om staak te voorspel. Die primêre oorweging was staak tydens simmetriese vlugte en behels slegs die voorkoming van staak deur gebruik te maak van die hei beheer oppervlak. ’n Model voorspellings sleur tempo beheeralgoritme is ontwikkel om die hei-roer dinamies te beperk sodat die invalshoek nie ’n sekere vooraf bepaalde limiet oorskry nie. Die staak voorkomings beheerstelsel is ontwerp om te funksioneer as ’n skakel beheer skema om die beperkings op die bestaande vlugbeheerstelsel te minimaliseer. Laastens was sagteware-in-die-lus simulasies gebruik om die teoretiese resultate, wat verkry is tydens die ontwikkeling van hierdie staak voorkomings beheer-strategie, te kontroleer. Om die robuusthied van hierdie beheeralgoritmes teen model onsekerhede te ondersoek, is ’n ergste-geval prestasie analise ook uitgevoer.
38
Acuna, Virgilio. "Using Unmanned Aerial Vehicles for Wireless Localization in Search and Rescue." FIU Digital Commons, 2017. https://digitalcommons.fiu.edu/etd/3646.
Full textAbstract:
This thesis presents how unmanned aerial vehicles (UAVs) can successfully assist in search and rescue (SAR) operations using wireless localization. The zone-grid to partition to capture/detect WiFi probe requests follows the concepts found in Search Theory Method. The UAV has attached a sensor, e.g., WiFi sniffer, to capture/detect the WiFi probes from victims or lost people’s smartphones. Applying the Random-Forest based machine learning algorithm, an estimation of the user's location is determined with a 81.8% accuracy.
UAV technology has shown limitations in the navigational performance and limited flight time. Procedures to optimize these limitations are presented. Additionally, how the UAV is maneuvered during flight is analyzed, considering different SAR flight patterns and Li-Po battery consumption rates of the UAV. Results show that controlling the UAV by remote-controll detected the most probes, but it is less power efficient compared to control it autonomously.
39
Rosenberg, Abigail Stella. "An Evaluation of a UAV Guidance System with Consumer Grade GPS Receivers." Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/194506.
Full textAbstract:
Remote sensing has been demonstrated an important tool in agricultural and natural resource management and research applications, however there are limitations that exist with traditional platforms (i.e., hand held sensors, linear moves, vehicle mounted, airplanes, remotely piloted vehicles (RPVs), unmanned aerial vehicles (UAVs) and satellites). Rapid technological advances in electronics, computers, software applications, and the aerospace industry have dramatically reduced the cost and increased the availability of remote sensing technologies.Remote sensing imagery vary in spectral, spatial, and temporal resolutions and are available from numerous providers. Appendix A presented results of a test project that acquired high-resolution aerial photography with a RPV to map the boundary of a 0.42 km2 fire area. The project mapped the boundaries of the fire area from a mosaic of the aerial images collected and compared this with ground-based measurements. The project achieved a 92.4% correlation between the aerial assessment and the ground truth data.Appendix B used multi-objective analysis to quantitatively assess the tradeoffs between different sensor platform attributes to identify the best overall technology. Experts were surveyed to identify the best overall technology at three different pixel sizes.Appendix C evaluated the positional accuracy of a relatively low cost UAV designed for high resolution remote sensing of small areas in order to determine the positional accuracy of sensor readings. The study evaluated the accuracy and uncertainty of a UAV flight route with respect to the programmed waypoints and of the UAV's GPS position, respectively. In addition, the potential displacement of sensor data was evaluated based on (1) GPS measurements on board the aircraft and (2) the autopilot's circuit board with 3-axis gyros and accelerometers (i.e., roll, pitch, and yaw). The accuracies were estimated based on a 95% confidence interval or similar methods. The accuracy achieved in the second and third manuscripts demonstrates that reasonably priced, high resolution remote sensing via RPVs and UAVs is practical for agriculture and natural resource professionals.
40
Lindsten, Fredrik. "Angle-only based collision risk assessment for unmanned aerial vehicles." Thesis, Linköping University, Department of Electrical Engineering, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-15757.
Full textAbstract:
This thesis investigates the crucial problem of collision avoidance for autonomous vehicles. An anti-collision system for an unmanned aerial vehicle (UAV) is studied in particular. The purpose of this system is to make sure that the own vehicle avoids collision with other aircraft in mid-air. The sensor used to track any possible threat is for a UAV limited basically to a digital video camera. This sensor can only measure the direction to an intruding vehicle, not the range, and is therefore denoted an angle-only sensor. To estimate the position and velocity of the intruder a tracking system, based on an extended Kalman filter, is used. State estimates supplied by this system are very uncertain due to the difficulties of angle-only tracking. Probabilistic methods are therefore required for risk calculation. The risk assessment module is one of the essential parts of the collision avoidance system and has the purpose of continuously evaluating the risk for collision. To do this in a probabilistic way, it is necessary to assume a probability distribution for the tracking system output. A common approach is to assume normality, more out of habit than on actual grounds. This thesis investigates the normality assumption, and it is found that the tracking output rapidly converge towards a good normal distribution approximation. The thesis furthermore investigates the actual risk assessment module to find out how the collision risk should be determined. The traditional way to do this is to focus on a critical time point (time of closest point of approach, time of maximum collision risk etc.). A recently proposed alternative is to evaluate the risk over a horizon of time. The difference between these two concepts is evaluated. An approximate computational method for integrated risk, suitable for real-time implementations, is also validated. It is shown that the risk seen over a horizon of time is much more robust to estimation accuracy than the risk from a critical time point. The integrated risk also gives a more intuitively correct result, which makes it possible to implement the risk assessment module with a direct connection to specified aviation safety rules.
41
Cannon, Brandon Jeffrey. "Fault Detection for Unmanned Aerial Vehicles with Non-Redundant Sensors." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5308.
Full textAbstract:
To operate, autonomous systems of necessity employ a variety of sensors to perceive their environment. Many small unmanned aerial vehicles (UAV) are unable to carry redundant sensors due to size, weight, and power (SWaP) constraints. Faults in these sensors can cause undesired behavior, including system instability. Thus, detection of faults in these non-redundant sensors is of paramount importance.The problem of detecting sensor faults in non-redundant sensors on board autonomous aircraft is non-trivial. Factors that make development of a solution difficult include both an inability to perfectly characterize systems and sensors as well as the SWaP constraints inherent with small UAV. An additional challenge is the ability of a fault-detection method to strike a balance between false-alarm rate and detection rate.This thesis explores two model-based methods of fault-detection for non-redundant sensors, a Kalman filter based method and a particle filter based method. The Kalman filter based method employs tests of mean and covariance on the normalized innovation sequence to detect faults, while the particle filter based method uses a function of the average particle weights.The Kalman filter based approach was implemented in real time on board an autonomous rotorcraft using an extended Kalman Filter (EKF). Faults tested included varied levels of bias, drift, and increased noise. Metrics included false-alarm rate, detection rate, and delay to detection. The particle filter based approach was implemented on a simulated system. This was then compared with an implementation of the EKF based approach for the same system. The same fault types and metrics were also used for these tests.The EKF based method of fault-detection performed well onboard the autonomous rotorcraft and should be generalizable to other systems for which an EKF or Kalman filter can be implemented. The theory indicates that the particle filter based algorithm should have performed better, though the simulations showed poor detection characteristics in comparison to the Kalman filter based method. Future work should be performed to explore improvements to the particle filter based method.
42
Newcomb, Jenna Elisabeth. "Trajectory Optimization and Design for a Large Number of Unmanned Aerial Vehicles." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7755.
Full textAbstract:
An unmanned aerial vehicle (UAV) swarm allows for a more time-efficient method of searching a specified area than a single UAV or piloted plane. There are a variety of factors that affect how well an area is surveyed. We specifically analyzed the effect both vehicle properties and communication had on the swarm search performance. We used non-dimensionalization so the results can be applied to any domain size with any type of vehicle. We found that endurance was the most important factor. Vehicles with good endurance sensed approximately 90% to 100% of the grid, even when other properties were lacking. If the vehicles lacked endurance, the amount of area the vehicles could sense at a given time step became more important and 10% more of the grid was sensed with the increase in sensed area. The maneuverability of the vehicles was measured as the vehicles' radii of turn compared to the search domain size. The maneuverability mattered the most in the middle-range endurance cases. In some cases 30% more of the grid was searched with improving vehicle maneuverability. In addition, we also examined four communication cases with different amounts of information regarding vehicle location. We found communication increased search performance by at least 6.3%. However, increasing the amount of information only changed the performance by 2.3%. We also studied the impact the range of vehicle communication had on search performance. We found that simulations benefited most from increasing the communication range when the amount of area sensed at a given time step was small and the vehicles had good maneuverability. We also extended the optimization to a multi-objective process with the inclusion of target tracking. We analyzed how the different weightings of the objectives affected the performance outcomes. We found that target tracking performance dramatically changes based on the given weighting of each objective and saw an increase of approximately 52%. However, the amount of the grid that was sensed only dropped by approximately 10%.
43
Cheng, Quan. "The Development of an FPGA-based Autopilot for Unmanned Aerial Vehicles." VCU Scholars Compass, 2006. http://scholarscompass.vcu.edu/etd_retro/112.
Full textAbstract:
This work is part of an on-going research project at Virginia Commonwealth University in the field of Unmanned Aerial Vehicles (UAVs). The purpose of this thesis project is to port the previous generation of UAV autopilot from the Atmel FPSLIC platform to the Xilinx MicroBlaze platform in order to provide a test-bed that will accommodate future research projects. The tasks include porting the software from the AVR processor located on the FPSLIC to the MicroBlaze processor and implementing the hardware peripherals in Xilinx FPGA.The UAV equipped with the new autopilot can autonomously navigate through pre-defined waypoints and transmit the collected data back to the ground base station for analysis.
44
Absetz, Erica. "Actual Entities: A Control Method for Unmanned Aerial Vehicles." VCU Scholars Compass, 2013. http://scholarscompass.vcu.edu/etd/3094.
Full textAbstract:
The focus of this thesis is on Actual Entities, a concept created by the philosopher Alfred North Whitehead, and how the concept can be applied to Unmanned Aerial Vehicles as a behavioral control method. Actual Entities are vector based, atomic units that use a method called prehension to observe their environment and react with various actions. When combining multiple Actual Entities a Colony of Prehending Entities is created; when observing their prehensions an intelligent behavior emerges. By applying the characteristics of Actual Entities to Unmanned Aerial Vehicles, specifically in a situation where they are searching for targets, this emergent, intelligent behavior can be seen as they search a designated area and locate specified targets. They will alter their movements based on the prehensions of the environment, surrounding Unmanned Aerial Vehicles, and targets.
45
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.
46
Gatzke, Benjamin Thomas. "Trajectory optimization for helicopter Unmanned Aerial Vehicles (UAVs)." Thesis, Monterey, California : Naval Postgraduate School, 2010. http://edocs.nps.edu/npspubs/scholarly/theses/2010/Jun/10Jun%5FGatzke.pdf.
Full textAbstract:
Thesis (M.S. in Applied Mathematics)--Naval Postgraduate School, June 2010.Thesis Advisor(s): Kang, Wei ; Second Reader: Zhou, Hong. "June 2010." Description based on title screen as viewed on July 14, 2010. Author(s) subject terms: Nonlinear model, trajectory optimization, state and control variables, cost function Includes bibliographical references (p. 59-60). Also available in print.
47
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
48
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.
49
Ernest, Nicholas D. "Genetic Fuzzy Trees for Intelligent Control of Unmanned Combat Aerial Vehicles." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1427813213.
Full text
50
ioannidis, ioannis. "Unmanned Aerial Vehicles and remote sensing in search and rescue missions in Sweden." Thesis, KTH, Fastigheter och byggande, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-266775.
Full textAbstract:
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.