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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.
801

Current use of smart lighting in the home environment

Kjellberg, Viktor, Högkvist, Albin January 2020 (has links)
Smart lighting has in more recent times developed into a broader market, where it has moved into people’s homes, as opposed to in the beginning when it was used more at office environments due to its benefits of high potential energy savings (Santamouris & Dascalaki, 2002). Today Smart LightingSystem (SLS) provides the opportunity for private home lighting fixtures and sensors to be connected wirelessly and connect with other internet of things (IoT) products to perform required tasks. Thus, the purpose of this study is to investigate if how Swedish residents use SLS at home. To answer this, we first needed to do an inventory of the homes currently using Smart lighting and if why it is being used. As a method for data collection of the study, a web-based survey including a mixed-question questionnaire was used with Single choice, Multiple-choice questions and a 7-Point Likert Scale. It consisted of 20 questions and got 114 respondents to answer about their usage of SLS. Out of these114, 39 participants were users of SLS. The raw data generated by the survey were analysed and visualized using descriptive statistics with tools like Pivotable and Pivot charts in Microsoft Excel. In general, Functionality is the most important aspect when investing in SLS across all age-groups and gender. Turn On/ Off and Dimming is the most common way of controlling the lights and the Smartphone for interaction in the home environment.
802

A CONTINOUS ROTARY ACTUATION MECHANISM FOR A POWERED HIP EXOSKELETON

Ryder, Matthew C 17 July 2015 (has links)
This thesis presents a new mechanical design for an exoskeleton actuator to power the sagittal plane motion in the human hip. The device uses a DC motor to drive a Scotch yoke mechanism and series elasticity to take advantage of the cyclic nature of human gait and to reduce the maximum power and control requirements of the exoskeleton. The Scotch yoke actuator creates a position-dependent transmission that varies between 4:1 and infinity, with the peak transmission ratio aligned to the peak torque periods of the human gait cycle. Simulation results show that both the peak and average motor torque can be reduced using this mechanism, potentially allowing a less powerful motor to be used. Furthermore, the motor never needs to reverse direction even when the hip joint does. Preliminary testing shows the exoskeleton can provide an assistive torque and is capable of accurate position tracking at speeds covering the range of human walking. This thesis provides a detailed analysis of how the dynamic nature of human walking can be leveraged, how the hip actuator was designed, and shows how the exoskeleton performed during preliminary human trials.
803

Experiment and Simulation of the Acoustic Signature of Fatigued-Cracked Gears in a Two-Stage Gearbox

Ostiguy, Matthew James 01 December 2014 (has links)
This thesis focuses on the development of a health monitoring system for gearbox transmissions. This was accomplished by developing and understanding a two-stage gearbox computer model that emulates an actual gearbox test rig. The computer model contains actual gearbox geometry, flexible shafts, bearings, gear contact forces, input motor torque, output brake torque, and realistic gearbox imbalance. The gear contact force of each gear stage and the input bearing translational acceleration were the main outputs compared between a healthy gearbox and damaged gearbox computer model. The damage of focus was a fatigue crack on the input pinion gear. A sideband energy ratio comparison yielded the computer simulation accurately modeled the difference between a healthy and damaged gearbox. The next step in this study involved the development of a repeatable procedure to initiate and propagate a fatigue crack at the tooth root in an actual spur gear. A damaged spur gear allows for a future comparison of an actual healthy and damaged gearbox system in the lab. A custom fatigue fixture was designed and manufactured for a Martin S1224BS 1 spur gear. The fatigue crack was initiated by position control fatigue testing which deflects the gear tooth a set amplitude for a number of cycles. Over the length of the test, the load that the tooth can withstand in bending decreases as damage begins to occur. Once the max load on the gear has dropped by a significant percentage (5-15%) a crack has initiated and begun to propagate across the tooth face. The use of a scanning electron microscope confirmed the presence a fatigue crack.
804

Design of a Low-Cost Data Acquisition System for Rotordynamic Data Collection

Pellegrino, Gregory S 01 March 2019 (has links)
A data acquisition system (DAQ) was designed based on the use of a STM32 microcontroller. Its purpose is to provide a transparent and low-cost alternative to commercially available DAQs, providing educators a means to teach students about the process through which data are collected as well as the uses of collected data. The DAQ was designed to collect data from rotating machinery spinning at a speed up to 10,000 RPM and send this data to a computer through a USB 2.0 full-speed connection. Multitasking code was written for the DAQ to allow for data to be simultaneously collected and transferred over USB. Additionally, a console application was created to control the DAQ and read data, and MATLAB code written to analyze the data. The DAQ was compared against a custom assembled National Instruments CompactDAQ system. Using a Bentley-Nevada RK 4 Rotor Kit, data was simultaneously collected using both DAQs. Analysis of this data shows the capabilities and limitations of the low cost DAQ compared to the custom CompactDAQ.
805

Automatická detekce ovládacích prvků výtahu zpracováním digitálního obrazu / Automatic detection of elevator controls using image processing

Černil, Martin January 2021 (has links)
This thesis deals with the automatic detection of elevator controls in personal elevators through digital imaging using computer vision. The theoretical part of the thesis goes through methods of image processing with regards to object detection in image and research of previous solutions. This leads to investigation into the field of convolutional neural networks. The practical part covers the creation of elevator controls image dataset, selection, training and evaluation of the used models and the implementation of a robust algorithm utilizing the detection of elevator controls. The conclussion of the work discusses the suitability of the detection on given task.
806

Controles topográficos en pendientes pronunciadas para evitar deslizamientos utilizando vehículos aéreos no tripulados (UAV) / Topographic control son steep slopes to prevent landslides using unmanned aerial vehicles (UAV)

Gibaja Bautista, Roberto Sebastian, Rojas Ruiz, Rodrigo David 18 August 2019 (has links)
El siguiente trabajo de investigación se realizó en la bajada de Armendáriz, acantilado de la Costa Verde, distrito de Miraflores, provincia de Lima, Perú. En este se propone la creación de una metodología de control topográfico en la zona anteriormente mencionada, esto debido a que se presentan constantes deslizamientos de rocas por diversos factores como la erosión marina y el tránsito vehicular cercano. Usando información del Instituto Geográfico Nacional (IGN), información brindada por profesionales en el área e información obtenida del vuelo fotogramétrico con dron Mavic 2 Pro realizado, se elaboró la comparación de perfiles longitudinales de los años 2019, 2020 y 2021 en una zona del talud que sufre deslizamientos de manera constante. Con el fin de mantener la precisión y coherencia de los resultados, se procesó la información obtenida para lograr las mismas características entre los planos de curvas de nivel que sirvieron para la realización de los cálculos y el posterior análisis. Entre los principales resultados obtenidos se determinó que la parte superior del talud se redujo 1.30 m durante los años evaluados, la parte media una reducción de 0.50 m y la parte inferior un incremento de 1.20 m. Con los resultados mencionados anteriormente se determinó la tendencia a sufrir derrumbes que posee la zona del talud evaluada y se propuso la realización de vuelos fotogramétricos anuales para el seguimiento del comportamiento del talud con el fin de implementar obras de ingeniería de contención en las zonas vulnerables. / The following research work was carried out in the Bajada de Armendariz, cliff of the Costa Verde, district of Miraflores, province of Lima, Peru. In this, the creation of a topographic control methodology in the aforementioned area is proposed, due to the fact that there are constant rock slides due to various factors such as marine erosion and nearby vehicular traffic. Using information from the National Geographic Institute (IGN), information provided by professionals in the area and information obtained from the photogrammetric flight with a Mavic 2 Pro drone carried out. the comparison of longitudinal profiles of the years 2019, 2020 and 2021 in an area of ​​the slope was elaborated that suffers landslides constantly. In order to maintain the precision and coherence of the results, the information obtained was processed to achieve the same characteristics between the contour planes that were used to carry out the calculations and the subsequent analysis. Among the main results obtained, it was determined that the upper part of the slope decreased 1.30 m during the evaluated years, the middle part a reduction of 0.50 m and the lower part an increase of 1.20 m. With the aforementioned results, the tendency to collapse in the area of ​​the evaluated slope was determined and it was proposed to carry out annual photogrammetric flights to monitor the behavior of the slope in order to implement containment engineering works in vulnerable areas. / Trabajo de investigación
807

Podpůrné měniče v elektrické trakci / Auxiliary inverters for electric traction

Polášek, Petr January 2009 (has links)
This thesis concerns with specified problems of an electric traction. It deals with the concept of module controlling EC motor of the voltage 24V and the current 100A. There are described possibilities and principles of controlling EC motor in detail. For controlling, the single-purpose IO MC33035, which is directly specified for it, is used. The thesis describes implementation of both testing and final versions of converter for a circulating pump drive of a cooling circuit in locomotives. The convertor is partly universal and can be used in other applications. According to the implemented convertor, a laboratory test and a model protocol were made. In the second part, the concept is described as well as the implementation of DC/DC conventor of output voltage of 24V and which is supplied by 12V battery. The specified output current is 4A. It is used for supplying of the controlling traction vehicle unit and is installed as a boost convertor which contains a resonance conventor. The presentation of measured parameters of the complete convertor is either a part of this thesis.
808

Apartmány Farské lúky, Čeladná - příprava a realizace stavby. / Apartments Farské lúky, Čeladná - preparation and realization construction.

Stach, Jakub January 2013 (has links)
The object of the diploma thesis is preparation and realization of the gross superstructure of apartment houses Farske luky in Celadna. Diploma thesis deals with facility of the building site, project of machines, technological rules of monolithic constructions, plans of quality controls, time and financial plan, works contract, schedule and work safety.
809

Stavebně technologický projekt modernizace objektu T8, VUT v Brně / Architectural and technological modernization project object T8, BUT

Skokanová, Šárka January 2015 (has links)
The subject of this diploma thesis is the architectural and technological modernization project object T8 the Technical University in Brno. Reconstruction of the partial operation affects investor during reconstruction and access to various floors of the building which is secured by a connecting bridge passing over five floors of the building and articulated halls adjacent buildings. The aim is to design technology solutions, spatio-temporal, financial and legislative aspects, taken on the basis of project documentation.
810

Motor-generátor s axiálním tokem pro hybridní autobus / Traction axial flux motor-generator for hybrid electric bus application

Odvářka, Erik January 2010 (has links)
Tato dizertační práce se zabývá návrhem původního motor-generátoru s axiálním tokem a buzením permanetními magnety, zkonstruovaným specificky pro hybridní elektrický autobus. Návrhové zadání pro tento stroj přineslo požadavky, které vedly k této unikátní topologii tak, aby byl dosažen výkon, účinnost a rozměry stroje. Tato partikulární topologie motor-generátoru s axiálním tokem je výsledkem literární rešerše, kterou následoval výběr koncepce stroje s představeným návrhem jako výsledkem těchto procesů. Přístup k návrhu stroje s axiálním tokem sledoval „multi-fyzikální“ koncepci, která pracuje s návrhem elektromagnetickým, tepelným, mechanickým, včetně návrhu řízení, v jedné iteraci. Tím je v konečném návrhu zajištěna rovnováha mezi těmito inženýrskými disciplínami. Pro samotný návrh stroje byla vyvinuta sada výpočtových a analytických nástrojů, které byly podloženy metodou konečných prvků tak, aby samotný návrh stroje byl přesnější a spolehlivější. Modelování somtného elektrického stroje a celého pohonu poskytlo představu o výkonnosti a účinnosti celého subsytému v rozmanitých operačních podmínkách. Rovněž poukázal na optimizační potenciál pro návrh řízení subsystému ve smyslu maximalizace účinnosti celého pohonu. Bylo postaveno několik prototypů tohoto stroje, které prošly intensivním testováním jak na úrovni sybsytému, tak systému. Samotné výsledky testů jsou diskutovány a porovnány s analytickými výpočty parametrů stroje. Poznatky získané z prvního prototypu stroje pak sloužily k představení možností, jak zjednodušit výrobu a montáž stroje v příští generaci. Tato práce zaznamenává jednotlivé kroky během všech fází vývoje elektrického stroje s axiálním tokem, počínaje výběrem konceptu stroje, konče sumarizací zkušeností získaných z první generace prototypu tohoto stroje.

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