• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 15
  • 8
  • 3
  • 1
  • Tagged with
  • 30
  • 14
  • 9
  • 9
  • 8
  • 6
  • 5
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 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.
21

Responding to Dangerous Accidents Among the Elderly: A Fall Detection Device with ZigBee-Based Positioning

Putnam, Michael R 01 September 2012 (has links) (PDF)
The following paper describes a fall detection and activity monitoring system with position detection based on Zigbee transceivers.The main objective is to reduce the time taken for emergency personnel to respond to falls among the elderly. Especially when the victim is unconscious or delirious, position tracking reduces location determination time within a busy hospital or nursing home environment and facilitates immediate treatment. Reduced response times correlate to decreased morbidity and mortality rates. Background is provided on the major wireless network advances currently deployed in a healthcare setting for asset and personnel tracking, etiology of falls, and several methods of detecting falls using sensors and image processing techniques. Data analysis proves that a precise coordinate tracking system was infeasible using the XBee RF module (based on the Zigbee protocol) due to environmental noise, a poor antenna construction and lack of precise signal strength measurements. A primitive scheme with lower resolution and higher reliability associating a single location with each Zigbee transceiver was employed. A pedometer function was added to the project to monitor the user’s daily activity and to potentially serve as a predictor of falls through the interpretation of mobility and gait patterns related to step counts.
22

Development of a wireless sensor system for the characterization of energy harvesting conditions

Hörschmeyer, Felix January 2016 (has links)
This report deals with the development of a wireless sensor system that measures the environmental energy and predicts if energy harvesting could be possible in different areas. It provides an overview over the hardware used to build this system and gives a detailed description of the software implementation of the system. The hardware part presents the microcontroller and platform that is used, as well as the sensors integrated in the system. The software part explains how the used hardware was put together in a program that controls the different components. It explains the possibility to save captured sensor values on an SD card or send them to a remote receiver with an XBee radio module in real time. Also the inclusion of the mbed software library, which provides a lot of useful applications and functions for the project, is an important part. The final part of the report presents the results, showing how the system works.
23

Koncentrátor pro dálkový sběr dat a bezdrátové moduly / Data concentrator for data acquisition and wireless modules

Palacký, Tomáš January 2015 (has links)
This master’s thesis deals with design and construction of a system for repote measurement of air quality in buildings. The first section provides a selection and analysis of used hardware and software components: minicomputer Raspberry Pi, STM32F401 microcontroller, communication module XBee-Pro, CO2 sensor and also communication interfaces IC and USART. The next section includes a design of electrical wiring, circuit board, configuration of the wireless modules and a software implementation for microcontroller and the concentrator.
24

Inteligentní senzorická síť navržená pro specifikaci 802.15.4 (beta aplikace) / Intelligent Sensory Net designed on the standard IEEE 802.15.4

Janšta, Tomáš January 2009 (has links)
This thesis focuses on design of wireless network nodes using modular construction parts with respect to IEEEŽ 802.15.4 standard. Presented platform joins the benefits of the XBeeŽ wireless module and the AVR ATmega128 microcontroller development system. Sensor network prototype is designed to meet the desired first attempt functionality of embedded platform for collection and delivery of small volumes of control and sensor data between the network and the gateway. The control software was developed for TinyOS operating system. Designed platform is used as the framework for future development and possible functionality extensions in related applications.
25

Wireless Sensor And Actuator Nodes For A Process Control Experiment

Wälivaara, Jesper January 2018 (has links)
This report details the work which has been done to redesign an older process control lab setup, in order for it to become fully modular and wirelessly controllable.The process control lab setup of interest was the quadruple water tank process. Asa proof of concept, a single prototype tank module of the quadruple tank setup wasto be redesigned, where this new design would use entirely modular and wirelesslycontrollable sensors and actuators. The design of these wireless devices was donefrom scratch, the end result was that a set of micro-controller based devices whichcommunicate over Xbee radios were manufactured. Control of this wireless tanksystem was achieved through a custom Simulink interface, said interface was alsocreated during this project. The finalized tank prototype system worked as intendedand it fulfilled all of the relevant system requirements regarding the sensor and actuator network design. There was originally a mechanical design component in thisproject which had to be left after the initial research stages due to time constraints,which concerned the construction of a new tank system. This prototype system wasa proof of concept, which proved the feasibility of building larger scale wirelesslycontrollable process control systems, such as the quadruple water tank process.
26

Experimental and Computational Study of Vibration-Based Energy Harvesting Systems for Self-Powered Devices

Alnuaimi, Saeed Khalfan 18 January 2021 (has links)
Energy harvesting of ambient and aeroelastic vibrations is important for reducing the dependence of wireless sensing and networks on batteries. We develop a configuration for a piezoelectric energy harvester with the capability to wirelessly communicate vibration measurements while using those vibrations to power the sensing and communication devices. Particularly, we perform experiments that aim at identifying challenges to overcome in the development of such a configuration. Towards that objective, we successfully tested a self-powered real-time point-to-point wireless communication system between a vibration sensor and transmission and receiving modules. The sensing device and transmission module are powered by the vibrating object using a piezoelectric energy harvester. The communication is established by using two XBee modules. In the second part of this dissertation, we address the optimization of the output power of piezoelectric energy harvesters of aeroelastic vibrations. Given the complexity of high-fidelity simulations of the coupling between the fluid flow, structural response and piezoelectric transduction, we develop and experimentally validate a phenomelogical reduced-order model for energy harvesting from wake galloping. We also develop a high-fidelity simulation for the same phenomena. The modeling and high-fidelity simulations can be a part of a multi-disciplinary optimization framework to be used in the design and operation of galloping-based energy harvesters. / Doctor of Philosophy / Energy harvesting of ambient or flow-induced vibrations is important for reducing the dependence on batteries in wireless sensing and networks to monitor deterioration conditions, environmental pollution or wildlife conservation. Balancing the benefits and shortcomings of a specific approach, namely piezoelctric transduction, for energy harvesting from vibrations, we address a specific challenge related to the development of a configuration that allows for communicating measured vibrations using their power. Furthermore, given the low levels of output power from piezoelectric transduction, we address the need to optimize power output levels through the development of predictive models that depend on geometry and speed of the fluid flow.
27

A fuzzy logic micro-controller enabled system for the monitoring of micro climatic parameters of a greenhouse

Sibiya, Malusi 10 1900 (has links)
Motivation behind this master dissertation is to introduce a novel study called " A fuzzy logic micro-controller enabled system for the monitoring of micro-climatic parameters of a greenhouse" which is capable of intelligently monitoring and controlling the greenhouse climate conditions in a preprogrammed manner. The proposed system consists of three stations: Sensor Station, Coordinator Station, and Central Station. To allow for better monitoring of the climate condition in the greenhouse, fuzzy logic controller is embedded in the system as the system becomes more intelligent with fuzzy decision making. The sensor station is equipped with several sensor elements such as MQ-7 (Carbon monoxide sensor), DHT11 (Temperature and humidity sensor), LDR (light sensor), grove moisture sensor (soil moisture sensor). The communication between the sensor station and the coordinator station is achieved through XBee wireless modules connected to the Arduino Mega and the communication between coordinator station and the central station is also achieved via XBee wireless modules connected to the Arduino Mega. The experiments and tests of the system were carried out at one of IKHALA TVET COLLEGE’s greenhouses that is used for learning purposes by students studying agriculture at the college. The purpose of conducting the experiments at the college’s green house was to determine the functionality and reliability of the designed wireless sensor network using ZigBee wireless technology. The experiment result indicated that XBee modules could be used as one solution to lower the installation cost, increase flexibility and reliability and create a greenhouse management system that is only based on wireless nodes. The experiment result also showed that the system became more intelligent if fuzzy logic was used by the system for decision making. The overall system design showed advantages in cost, size, power, flexibility and intelligence. It is trusted that the results of the project will give the chance for further research and development of a low cost greenhouse monitoring system for commercial use. / Electrical and Mining Engineering / M. Tech. (Electrical Engineering)
28

Bezdrátový systém pro vyhodnocení řízení osvětlení v budovách s cílem získat informace vedoucí k úsporám / Wireless System for Evaluation of Lighting Control in Buildings for Obtaining Information Leading to Savings

Malinowski, Radim January 2015 (has links)
The aim of the thesis is to design a system based on wirelessly comunicating devices that will be able to record an information about persons presesce in certain area. Aquired data will served for evaluation of the area lighting system efficiency. Partial goals related to this work are: to analyze electricity consumption mesaurement methods, to analyze presence and movement detection methods, to analzye wireless communication methods, to desin system's HW and SW including realization, to put system into a real operation and finally, to evaluate measured data.
29

Návrh a realizace bezdrátového interface ODBII-XBee / Design and realization of wireless interface ODBII-XBee

Zatloukal, Martin January 2010 (has links)
This master’s thesis describes possibilities of usage of ZigBee communication protocol and integrated circuit ELM 327 in problem of realization universal diagnostic device, running by OBDII communication standards, which can be used to monitor function of all car´s electronic systems. Thesis also deals with design and realization of necessary electro technical devices and modules followed by compilation of control software and experimental measurements of these devices in real traffic flow. In the first part of project, there are reminded some basic features and parameters of OBDII, followed by description of ways how to use OBDII and adumbrating how to realize universal diagnostic system. The analysis of ZigBee system focused on XBee circuits follows. Construction, ways of data transfer and possibilities of controlling are described. Integrated circuits produced by ELM Electronics Company are introduced and possibilities of usage ELM 327 are described as requested by main task. Second part talks about designing of electronic circuits of this system, assembling schematic diagram and designing sources for production of PCB. Physical realization of these circuits and its first start is also included. Thesis finishes by dealing with practical experiences and measurements using real vehicles. This part talks also about means to improve system by several software solutions to reach more effective functioning of created device.
30

A 3D-printed Fat-IBC-enabled prosthetic arm : Communication protocol and data representation

Engstrand, Johan January 2020 (has links)
The aim of this thesis is to optimize the design of the Fat-IBC-based communication of a novel neuroprosthetic system in which a brain-machine interface is used to control a prosthetic arm. Fat-based intra-body communication (Fat-IBC) uses the fat tissue inside the body of the bearer as a transmission medium for low-power microwaves. Future projects will use the communication system and investigate ways to control the prosthetic arm directly from the brain. The finished system was able to individually control all movable joints of multiple prosthesis prototypes using information that was received wirelessly through Fat-IBC. Simultaneous transmission in the other direction was possible, with the control data then being replaced by sensor readings from the prosthesis. All data packets were encoded with the COBS/R algorithm and the wireless communication was handled by Digi Xbee 3 radio modules using the IEEE 802.15.4 protocol at a frequency of 2.45 GHz. The Fat-IBC communication was evaluated with the help of so-called "phantoms" which emulated the conditions of the human body fat channel. During said testing, packet loss measurements were performed for various combinations of packet sizes and time intervals between packets. The packet loss measurements showed that the typical amount of transmitted data could be handled well by the fat channel test setup. Although the transmission system was found to be well-functioning in its current state, increasing the packet size to achieve a higher granularity of the movement was perceived to be viable considering the findings from the packet loss measurements.

Page generated in 0.0369 seconds