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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An Indoor Localization System Based on BLE Mesh Network

Silver, Oscar January 2016 (has links)
Internet of Things (iot) is a growing field enabled by many different technologies. One of these technologies is  Bluetooth Low Energy (ble). It is of interest to investigate the potential of ble and one interesting, currently unsupported, feature is mesh networking. This thesis work aims to investigate whether it is possible to design and implement a mesh network protocol using ble. To verify the implemented mesh network protocols functionality an indoor localization system has been implemented upon the BLE mesh network protocol. Furthermore this thesis work investigates if an indoor localization system can benefit from using a mesh network. The results of the investigation is a proof of concept of a functional ble mesh network protocol implemented on hardware and tested in a real environment. Tests show that the implemented localization system has similar accuracy as other rssi based indoor localization systems. The largest advantage found for a mesh based indoor localization is the ability to localize objects outside of the radio propagation range of the user. This feature is enabled by multi-hop messaging in the mesh network.
2

Wireless control of wall switches : A module that controls your existing wall switch with an application / Trådlös styrning av väggströmbrytare

Örjegård, Johan January 2017 (has links)
In this project a home-automation-solution is developed that wirelessly can control an existing wall switch with an application from a smart device. The purpose of the project is to develop a new solution that doesn’t require any electrical knowledge to mount the solution. Exiting solutions for controlling a switch require a module that is connected in series with the switch. The project will develop a module that can be mounted next to the selected wall switches to control them without electrical connection to the AC-voltage of the switch. Instead there is a servo that physically press the switch that is controlled. The servo motor is controlled wirelessly via Bluetooth Low Energy using an Android application, thus, a force is applied to the switch to turn on or off. A rechargeable lithium battery of 3.7 volts powers the whole module. Therefore, a "power-board" was developed that step up the voltage to 5 V. There are also components on the board that manage battery charging via microUSB. The Android application communicates via a Bluetooth Low Energy module that is mounted on a CPU board and has been developed and specifically manufactured to fit into the project. Both the power-board and processor-board is developed from own drawings and PCB layouts, and made with a manual etching method. The chassis has also been designed and manufactured with a 3D printer. The chassis holds all circuit boards, battery and a mount for the servo. The result is a working prototype that can be mounted on a switch and then operate the switch within the range of BLE. The prototype has a run time of each charging cycle of about 60 days under conditions that it is operated, on average, three times per day. / I detta projekt utvecklas en hemautomationslösning som kan styra befintliga väggströmbrytare trådlöst via en applikation från en smart enhet. Syftet med projektet är att utveckla en ny lösning där det inte krävs någon elinstallationskunskap för att montera lösningen. Dagens lösningar för att trådlöst styra en strömbrytare kräver att en modul kopplas in i serie med strömbrytaren. I projektet utvecklas en modul som kan monteras bredvid utvalda strömbrytare för styrning av dem utan att behöva ansluta sig galvaniskt till brytarens starkström. I stället sitter en servomotor i modulen som fysiskt trycker på den strömbrytare som skall styras. Servomotorn kan styras trådlöst via Bluetooth Low Energy med hjälp av en androidapplikation, på så sätt appliceras en kraft på brytarvippan och slå på eller av den. Hela modulen är strömförsörjd av ett laddningsbart litiumbatteri på 3,7 volt. Därför har ett spänningskort utvecklats som växlar upp spänningen till 5 V. På spänningskortet finns även komponenter som hanterar laddning av batteriet via microUSB. Applikationen kommunicerar via en BLE-modul som i sin tur sitter monterad på ett processorkort som har utvecklats och tillverkas speciellt för att passa in i detta projekt. Både spänningskortet och processorkortet är utvecklade ifrån egna ritningar och PCB-layouter samt tillverkade med en manuell etsningsmetod. Ett chassi har också konstruerats och tillverkats med en 3D-skrivare. Chassit rymmer alla kretskorten, batteriet och har ett motorfäste för montering av servomotorn. Resultat har blivit en fungerande prototyp som kan monteras på en strömbrytare och därefter manövrera brytaren inom den räckvidd som BLE klarar av. Prototypen har en drifttid på cirka 60 dagar under förutsättningar att den manövreras i genomsnitt vid tre tillfällen per dygn.
3

Meshnetwork of wireless IoT sensors / Meshnätverk av trådlösa IoT sensorer

Olsson, Alexander January 2016 (has links)
The Internet of things is a scenario where devices such as lighting, household appliances, sensors etc. are connected and communicate with each other via Internet. This puts a demand for a good infrastructure around these devices. One way to handle this is to use radio as a means of communication and let the devices forward each other's traffic in what is known as a mesh network. This thesis explores different radio standards that can be used to create a mesh network for sensors. Two different approaches to mesh networking using Bluetooth Low Energy was implemented and evaluated. One approach works by letting all devices broadcast every message they receive, a rather brute force approach. The other approach worked by letting the network find routes between all the nodes in the network and then establishes a connection between the nodes that want to communicate via intermediate nodes. It was found that the rebroadcast approach in idle mode used 3.36 mAh while the connection approach used 0.47 mAh for the same configuration. Another test was performed where the percentage of successfully delivered messages was measured. For the rebroadcast approach it was 75 % and for connection it was 58 %. Tweaking the connection network to not be able to adapt to changes increased the throughput to 77 %. During the testing numerous ways for improving performance were thought of but not implemented. The need for synchronizing the devices clocks and establishing protocol for when to send and receive became apparent when working with the rebroadcast network. In the connection network there were problems with that the routing maintenance led to unavailable units and reduced performance. / Sakernas internet, Internet of Things är ett scenario där elektriska apparater så som belysning, hushållsmaskiner, sensorer mm är anslutna och kommunicerar med varandra via internet. Men så många anslutna enheter ställer stora krav på infrastrukturen kring enheterna. Ett sätt att lösa problemen kring infrastruktur är att låta enheterna kommunicera via radio och låta dem vidarebefordra varandras datatrafik i en typ av nätverkstopologi som kallas för meshnätverk. Det här examensarbetet utforskar möjliga radiostandarder som kan användas för att skapa ett meshnätverk för just sensorer. Två typer av meshnätverk implementerades med Bluetooth Low Energy och deras styrkor och svagheter utvärderades. En av dessa gick ut på att enheterna i nätverket sände ut meddelanden som alla kunde ta och sedan att de som lyckades ta emot i sin tur sände meddelandena vidare. Det är en enkel metod som är lätt att implementera.Den andra metoden gick ut på att nätverket tog reda på sin konfiguration och vilken rutt som ska tas via andra enheter för att nå den man vill. När enheterna sen vill kommunicera så upprättar de en anslutning via enheterna längs rutten. Två saker som jämfördes mellan metoderna var strömförbrukning och andel lyckade sändningar. För samma nätverk så drog återsändnings nätverket 3.36 mA och anslutningsnätverket 0.47 mA. Antalet lyckade sändningar testades i ett annat scenario och där kom 75 % av meddelanden i återsändningsnätverket fram och motsvarande siffra för anslutningsnätverket var 58\%. Vidare testades det att stänga av utbytet av rutt information och sökningar efter nya enheter i anslutningsnätverket och då kom 77 % av meddelanden fram. I återsändningsnätverket insåg man att det fanns ett behov av att synkronisera klockorna i enheterna och etablera ett protokoll för hur när man ska sända och ta emot.I anslutningsnätverket så uppstod problem med att enheterna blev otillgängliga när de synkroniserade sin konfiguration vilket ledde till försämrad prestanda.
4

Samantha: A Social Location-Based Framework for iOS Applications

Newbry, Joe S 01 January 2014 (has links)
One challenge associated with developing location-based social applications for iOS devices is building a framework on top of Apple’s Core Bluetooth Framework to drive user discovery. Many applications on Apple’s App Store use Bluetooth to enable location-based user discovery. These Social Location-Based Frameworks are private and often are lacking. An ideal Social Location-Based Bluetooth Framework would be public, would be responsive while the application is minimized, have a light battery footprint, and securely transfer the necessary data to enable social interaction. Samantha, a Social Location-Based Framework, meets all of these characteristics. In a Test Application, Samantha took no more than 5 seconds to start up and discover all nearby users. The average discovery time was 3.5 seconds. In addition the battery draw, measured using Apple’s Battery Monitoring Instrument, during testing never exceed 1/20. This means an application running Samantha in the background for a 12-hour period would not significantly drain the battery. In terms of security, Samantha transfers a Unique User Identifier (UUID) across Bluetooth than contains no sensitive information. This UUID, a string of random characters, contains no personal information and it is only useful because it allows specific identification of a nearby user in a database holding additional information. This two-step process ensures that confidential information is never exposed. An example application, Ripple, uses Samantha to create a location-based social application and highlights the framework’s intended use.
5

Implementation of Sensor and Communication Technology for PAL Products

Månsson, Max, Lidbeck, Erik January 2020 (has links)
DD Company AB wanted to improve their existing products the football training rebounding board PAL and their PAL Cones. Their suggested solution was to create an application which communicates with PAL and PAL Cones via Bluetooth. The goal was to have an app which can record how many times PAL has been hit during a set time span and control PAL Cones to indicate to the player to step on a specific cone. PAL's problem was solved by on it place a base unit made of an accelerometer to sense impacts, a BLE112 Bluetooth module to communicate over Bluetooth and an Arduino UNO for reading the accelerometer and signal the Bluetooth module which transmits a hit counter over Bluetooth to the mobile application. The PAL Cone uses only the BLE112, a LED, a button and a button cell battery to keep the size to a minimum. The base unit is able to filter the initial impact from the residual vibrations and sends a updating hit counter over a Bluetooth connection to the mobile application. The mobile application can control the counter by sending commands to the base unit. After a hit the mobile application can activate a cone to light up and receives feedback when a player steps on the specified cone.
6

Performance measurements and analysis of bluetooth low energy

LINHARES, André Guedes 17 May 2016 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-07-12T13:37:34Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Master_Dissertation___Performance_Measurements_and_Analysis_of_Bluetooth_Low_Energy (8).pdf: 8669109 bytes, checksum: cb0af886f0cdc7babced229049a33535 (MD5) / Made available in DSpace on 2017-07-12T13:37:34Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Master_Dissertation___Performance_Measurements_and_Analysis_of_Bluetooth_Low_Energy (8).pdf: 8669109 bytes, checksum: cb0af886f0cdc7babced229049a33535 (MD5) Previous issue date: 2016-05-17 / The Internet of Things (IoT) paradigm has been rapidly gaining ground in the academic and industry communities as one of the most important emerging technologies. Some wireless communication technologies such as Bluetooth Low Energy (BLE) have been pointed as key technologies that will drive IoT applications. In order to leverage the BLE technology in IoT applications and identify the niche of applications this technology is more suitable, it is essential we have a deep understanding regarding some features such as link capacity, data transfer delay, connection establishment latency, and power consumption. This work evaluates the networking capabilities from BLE in scenarios of data transfer and connection establishment. The metrics maximum throughput, one-way delay, round-trip time, and connection establishment latency are evaluated through experimental measurements and we investigate how some factors (e.g. connection interval, pairing, packet size) impact on these metrics. Finally, this work proposes analytical models for the metrics investigated. / O paradigma da Internet das Coisas (Internet of Things - IoT) tem recebido grande destaque tanto das comunidades científicas como da indústria nos últimos anos. Algumas tecnologias de comunicação sem fio como Bluetooth Low Energy (BLE) tem sido apontadas como tecnologias que terão um papel fundamental na concepção de aplicativos de IoT. Um entendimento profundo de algumas características da tecnologia, como vazão e atraso na transmissão de dados, latência no estabelecimento de conexão e consumo de energia, é essencial para explorar ao máximo a tecnologia em cenários de IoT e identificar o nicho de aplicação onde esta tecnologia é mais aplicável. Este trabalho apresenta uma avaliação de desempenho da tecnologia BLE em cenários de transmissão de dados e estabelecimento de conexão. As métricas vazão máxima, atraso fim-a-fim, atraso ida-e-volta (Round-Trip Time - RTT) e latência de estabelecimento de conexão são avaliadas através de experimentos. Este trabalho também investiga como alguns fatores, como intervalo de conexão, encriptação de link e tamanho de pacote, impactam nas métricas avaliadas. Por fim, este trabalho apresenta modelos analíticos para as métricas investigadas.
7

Wearable EMG sensor och kraftmätning med trådtöjningsgivare / Wearable EMG Sensor with Strain Gauge Force Measurement

Stedt, Viktor January 2020 (has links)
Vid träning av baksida lår kan det vara svårt att förstå hur muskeln aktiveras. Genom att visualisera de myoelektriska signalerna från biceps femoris och semimembranosus till den som tränar kan personen få en bättre mind-muscle connection. I examensarbetet har två teoretiska EMG sensorer skapats och simulerats, kod har skrivits för att filtrera fyra EMG signaler samt överföra dessa över BLE, kraftsensorer är kopplade och kod är skriven för att avgöra den kraftutveckling som sker i en kontraktion av baksida lår. EMG sensorerna har jämförts med SparkFuns MyoWear muskelsensor, OpenBCI Cyton board och BioNomadix BN-EMG2-T. Båda de teoretiska lösningarna anses likvärdiga med ett billigare alternativ till Cryton Board, en flerkanalig lösning till MyoWear, BN-EMG2-T är för dyr att realistiskt implementeras till examensarbetets syfte. Simuleringarna visar att kretsarna behandlar signalen enligt tänkt sätt men det gick inte att bygga en prototyp då en pandemi har begränsat KTH:s verksamhet / One difficulty when training hamstrings is the understanding of how the muscle is activated. Through visualization of the myoelectrical signals from biceps femoris and semimembranosus to the exerciser, a better mind-muscle connection can be achieved. In this bachelor thesis, two theoretical EMG sensors were created and simulated, code to filter four EMG signals and transmit them through BLE was written, also a way to calculate how much force is applied in a hamstring curl was constructed. Both EMG sensors have been compared against SparkFuns MyoWear muscle sensor, OpenBCI Cyton Board and BioNOmadix BN-EMG2-T. The theoretical EMG sensors are interconvertible to a cheaper Cyton Board, a multichannel alternative to MyoWear, the BN-EMG2-T is too expensive to be a realistic alternative for this bachelor thesis attended purpose. Simulations show that the EMG sensors behave as intended but because of a pandemic, a prototype could not be created.
8

DMX-communication over Bluetooth low energy mesh network

Danielsson, Thomas January 2019 (has links)
With the addition of mesh capability to Bluetooth low energy(BLE) in 2017 new possibilities open up for the Internet of Things applications of Bluetooth. With the rapidly increasing number of connected devices a few new standards are competing for being the standard protocol for low power mesh communication. BLE is mostly aimed towards low bandwidth data such as sensor readings or light control. However, this thesis attempts to investigate the viability of adapting BLE mesh nodes to communicate DMX-data which is a protocol widely used in lightning and stage effects. The system is implemented on Bluetooth development kits and the latency and power consumption are measured. The results show that the latency is significant and with high variance if the full DMX frame is transmitted, rendering the application non-applicable on many real-time applications. It can however be justified in some applications due to Bluetooth's well established eco-system of devices and functionality where the nodes could extend their capabilities by implementing already established BLE models. By only transmitting the updated channels the latency can be lowered to values that would in some applications be indistinguishable from wired connection. The energy consumption of BLE mesh suffers greatly with the addition of mesh due to its constant scanning but by implementing low power nodes which keep the radio off during certain intervals this consumption could be greatly decreased. The results also show a high variance of latency depending on the node configuration regarding to the placements and the number of hops required to reach the intended recipient. / Bluetooth har länge varit standardprotokollet för kommunikation mellan två stycken enheter. 2017 kom tillägget med mesh till Bluetooth. Mesh innebär att andra enheten i närheten ska skicka vidare meddelanden och därigenom tillåta kommunikation mellan enheter som är utanför direkt radiokontakt. DMX är ett protokoll som används inom ljus- och sceneffekter. Bluetooth mesh är utformat för att skicka små datamängder som till exempel sensordata eller styra glödlampor. Denna uppsats kommer utvärdera om det är användbart att skicka DMX-data över Bluetooth mesh. En implementation gjordes på Bluetooth utvecklingskort och resultatet visar på en signifikant fördröjning och med hög varians vid överföring av alla DMX-kanaler, vilket innebär att denna implementation inte är användbar vid många användningsområden. Men trots det kan den vid vissa fall vara användningsbar, mycket till hjälp av Bluetooths billiga och utbyggda ekosystem av produkter och tilläggsfunktioner. Eftersom Bluetooth mesh byggs in i en del befintliga byggnader kan de uppoffringar man får göra vid överföringar av DMX-data vara acceptabel då man kan uttnyttja befintliga nät. Strömförbrukningen ökar avsevärt vid mesh jämfört med klassisk lågenergi Bluetooth då mesh måste skanna radiotrafiken konstant. Vid implementationen av lågenergi noder kan dock radio vara i stand-by och starta endast vid speciella tidpunkter och man kan därigenom få avsevärt lägre strömförbrukning, med uppoffringen att DMX-datan inte kan överföras omgående. Det visade sig också att noduppställningen kraftigt påverkade variansen i överföringshastighet och att detta måste ta i hänsyn vid valet om DMX över Bluetooth mesh är användbart i just det fallet.
9

Demonstrator Development for Phone as a Key Based on Bluetooth Low Energy

Karlsson, Eric, Lagerbielke, Alexander January 2017 (has links)
In this work a demonstrator for phone as a key has been developed. This demonstrator estimates the position of a mobile device in and around a test vehicle. Trilateration, ROCRSSI and fingerprinting with neural networks have been investigated for the localization of the mobile device. To filter the input data Kalman filter and average mean filter have been investigated. The best performing technique was determined to be the use of neural networks with a Kalman filter. The resulting demonstrator can determine if the mobile device is within the ranges of three predefined zones for the technology and three zones defined in the thesis. The demonstrator can estimate the location of the mobile device in real-time for these zones.
10

Localization, Visualization And Evacuation Guidance System In Emergency Situations

Tang, Jingyan 13 July 2016 (has links)
Urban search and rescue is needed for a variety of emergencies or disasters, including tornadoes, floods, dam failures, technological accidents, and terrorist activities. The efficiency to save people is becoming very important. With the development of the technology, people are trying to find a better way to help people get out of the dangerous places as soon as possible. DIORAMA system has been proposed to help with this problem and turns out very successful on improving efficiency during emergency situation. However, the current DIORAMA system is not perfect for all scenarios, for example, there are some outdoor environments do not support GPS service. Also, the RFID reader is very heavy for responders to carry and the indoor environment is not applicable for DIORAMA system. Besides, there are lack of forensic visualization toolkits that are able to help the incident commander analyze the responders’ behavior and efficiency. In this project, we propose a Localization, Visualization and Evacuation Guidance System in Emergency Situations. The functionalities in this system include localization in outdoor environments using BLE. Besides, for outdoor environments, some forensic visualization toolkit that can help the responder analyze the responders’ behavior with the capability of visualization and representation of data clearly as well as replay the task, detect anomalies and visualize the anomalies clearly is also provided in improving the efficiency and organization in the future task. In addition, the system also includes an indoor localization, navigation guidance and visualization system that provides guidance for people to exit a dangerous building as soon as possible. This system is able to localize the position of evacuees, and construct the exit path that helps reduce the escape time as well as provide a navigation guidance that is able to guide the user to the exit. In addition, an analyst simulation application is provided to simulate the evacuees in a building and evaluate the evacuation time for evacuees given specific path generation algorithm.

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