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Ultra-low power energy harvesting wireless sensor network designZheng, Chenyu January 1900 (has links)
Master of Science / Department of Electrical and Computer Engineering / William B. Kuhn and Balasubramaniam Natarajan / This thesis presents an energy harvesting wireless sensor network (EHWSN) architecture customized for use within a space suit. The contribution of this research spans both physical (PHY) layer energy harvesting transceiver design and appropriate medium access control (MAC) layer solutions. The EHWSN architecture consists of a star topology with two types of transceiver nodes: a powered Gateway Radio (GR) node and multiple energy harvesting (EH) Bio-Sensor Radio (BSR) nodes. A GR node works as a central controller to receive data from BSR nodes and manages the EHWSN via command packets; low power BSR nodes work to obtain biological signals, packetize the data and transmit it to the GR node.
To demonstrate the feasibility of an EHWSN at the PHY layer, a representative BSR node is designed and implemented. The BSR node is powered by a thermal energy harvesting system (TEHS) which exploits the difference between the temperatures of a space suit's cooling garment and the astronaut's body. It is shown that through appropriate control of the duty-cycle in transmission and receiving modes, it is possible for the transceiver to operate with less than 1mW power generated by the TEHS. A super capacitor, energy storage of TEHS, acts as an energy buffer between TEHS and power consuming units (processing units and transceiver radio). The super capacitor charges when a BSR node is in sleep mode and discharges when the node is active. The node switches from sleep mode to active mode whenever the super capacitor is fully charged. A voltage level monitor detects the system's energy level by measuring voltage across the super capacitor.
Since the power generated by the TEHS is extremely low(less than 1mW) and a BSR node consumes relatively high power (approximately 250mW) during active mode, a BSR node must work under an extremely low duty cycle (approximately 0.4%). This ultra-low duty cycle complicates MAC layer design because a BSR node must sleep for more than 99.6% of overall operation time. Another challenge for MAC layer design is the inability to predict when the BSR node awakens from sleep mode due to unpredictability of the harvested energy. Therefore, two feasible MAC layer designs, CSA (carrier sense ALOHA based)-MAC and GRI (gateway radio initialized)-MAC, are proposed in this thesis.
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A testbed implementation of energy efficient wireless sensor network routing protocols / Joubert George Jacobus KrigeKrige, Joubert George Jacobus January 2014 (has links)
Wireless Sensor Networks (WSNs) consist of Sensor Nodes (SNs) spatially removed
from one another, that can monitor a variety of environmental conditions. SNs then
collaboratively communicate the collected information to a central location, by passing
along the data in a multi-hop fashion. SN energy resources are limited and energy
monitoring and preservation in WSNs are therefore very important. Since multi-hop
communication takes place, the routing protocol used may have a significant effect on
the balanced use and preservation of energy in the WSN.
A significant amount of research has been performed on energy efficient routing in
WSNs, but the majority of these studies were only implemented in simulation. The
simulation engines used to perform these studies do not take into account all of the
relevant environmental factors affecting energy efficiency. In order to comment on the
feasibility of a routing protocol meant to improve the energy efficiency of a WSN, it is
important to test the routing scheme in a realistic environment.
In this study, a SN specifically designed to be used in an energy consumption ascertaining
WSN testbed was developed. This SN has a unique set of features which makes
it ideal for this application. Each SN is capable of recording its own power consumption.
The design also features a lithium battery charging circuit which improves the
reusability of the SN. Each node has a detachable sensor module and transceiver module
which enables the researcher to conduct experiments using various transceivers
and sensors. Twenty of these SNs were then used to form an energy consumption
ascertaining WSN testbed.
This testbed was used to compare the energy consumption of a Minimum Total Transmission
Power Routing (MTTPR) scheme to a shortest hop path routing scheme. The
results show that each SN’s transmission power setting dependant efficiency has a significant
effect on the overall performance of the MTTPR scheme. The MTTPR scheme
might in some cases use more energy than a shortest hop path routing scheme because
the transmission power setting dependant efficiency of the transceiver is not taken into account. The MTTPR scheme as well as other similar routing schemes can
be improved by taking the transceiver efficiency at different transmission power settings
into account. Simulation environments used to evaluate these routing schemes
can also be improved by considering the transceiver efficiency at different transmission
power settings. / MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2014
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A testbed implementation of energy efficient wireless sensor network routing protocols / Joubert George Jacobus KrigeKrige, Joubert George Jacobus January 2014 (has links)
Wireless Sensor Networks (WSNs) consist of Sensor Nodes (SNs) spatially removed
from one another, that can monitor a variety of environmental conditions. SNs then
collaboratively communicate the collected information to a central location, by passing
along the data in a multi-hop fashion. SN energy resources are limited and energy
monitoring and preservation in WSNs are therefore very important. Since multi-hop
communication takes place, the routing protocol used may have a significant effect on
the balanced use and preservation of energy in the WSN.
A significant amount of research has been performed on energy efficient routing in
WSNs, but the majority of these studies were only implemented in simulation. The
simulation engines used to perform these studies do not take into account all of the
relevant environmental factors affecting energy efficiency. In order to comment on the
feasibility of a routing protocol meant to improve the energy efficiency of a WSN, it is
important to test the routing scheme in a realistic environment.
In this study, a SN specifically designed to be used in an energy consumption ascertaining
WSN testbed was developed. This SN has a unique set of features which makes
it ideal for this application. Each SN is capable of recording its own power consumption.
The design also features a lithium battery charging circuit which improves the
reusability of the SN. Each node has a detachable sensor module and transceiver module
which enables the researcher to conduct experiments using various transceivers
and sensors. Twenty of these SNs were then used to form an energy consumption
ascertaining WSN testbed.
This testbed was used to compare the energy consumption of a Minimum Total Transmission
Power Routing (MTTPR) scheme to a shortest hop path routing scheme. The
results show that each SN’s transmission power setting dependant efficiency has a significant
effect on the overall performance of the MTTPR scheme. The MTTPR scheme
might in some cases use more energy than a shortest hop path routing scheme because
the transmission power setting dependant efficiency of the transceiver is not taken into account. The MTTPR scheme as well as other similar routing schemes can
be improved by taking the transceiver efficiency at different transmission power settings
into account. Simulation environments used to evaluate these routing schemes
can also be improved by considering the transceiver efficiency at different transmission
power settings. / MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2014
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Robust communication for location-aware mobile robots using motesMulanda, Brian Wise January 1900 (has links)
Master of Science / Department of Computing and Information Sciences / David A. Gustafson / The best mode of communication for a team of mobile robots deployed to cooperatively perform a particular task is through exchange of messages. To facilitate such exchange, a communication network is required. When successful execution of the task hinges on communication, the network needs to be robust - sufficiently reliable and secure. The absence of a fixed network infrastructure defeats the use of traditional wire-based communication strategies or an 802.11-based wireless network that would require an access point. In such a case, only an ad hoc wireless network is practical.
This thesis presents a robust wireless communication solution for mobile robots using motes. Motes, sometimes referred to as smart dust, are small, low-cost, low-power computing devices equipped with wireless communication capability that uses Radio Frequency (RF). Motes have been applied widely in wireless sensing networks and are typically connected to sensors and used to gather information about their environment. Communication in a mote network is inherently unreliable due to message loss, exposed to attacks, and supports very low bandwidth. Additional mechanisms are therefore required in order to achieve robust communication.
Multi-hop routing must be used to overcome short signal transmission range. The ability of a mobile robot to determine its present location can be exploited in building an appropriate routing protocol. When present, information about a mobile robot's future location can aid further the routing process. To guarantee message delivery, a transport protocol is necessary. Optimal packet sizes should be chosen for best network throughput. To protect the wireless network from attacks, an efficient security protocol can be used.
This thesis describes the hardware setup, software configuration, and a network protocol for a team of mobile robots that use motes for robust wireless communication. The thesis also presents results of experiments performed.
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Global Resource Utilization for Synergetic Wireless Sensor NetworksOteafy, Sharief M. A. 28 August 2013 (has links)
In a domain with diverse multi-disciplinary views of what a Wireless Sensor Network (WSN) is, tracking progress and developing efficient WSNs is inherently a complex process. The main motivation of this work is advancing state-of-the-art WSNs by adaptively utilizing their components, and enlisting the utility of resources in network vicinity. As WSNs increase in density and expand in scale, we continue to witness an increase in overlapped deployments that serve independent applications. In most scenarios, new networks are deployed for new applications without considering previous or neighboring WSNs.
This thesis presents the resource reuse (RR-WSN) paradigm. Adopting a generic framework for resource utilization, we achieve synergy between heterogeneous sensing systems. We abstract the view of a WSN in terms of functional capabilities, and offer a component-based view to boost sensor node (SN) potential and contribution to WSN operation. Thus SNs provide resources. On the other hand, we formally derive a set of functional requirements per application. The design and deployment of WSNs thus converges to an optimal assignment of functional requirements to resources.
Two mainstream designs of WSNs are addressed in this thesis. The first involves WSNs with static deployments of nodes, whereby multiple applications run on networks in a given vicinity, yet the resources and applications share an owner (e.g., on a University Campus). We then present a Binary Integer Programming formulation to find the optimal assignment of resources to these functional requirements, while minimizing the energy impact of running each functional request.
We further extend our scope to include WSNs that depend on transient nodes, such as smartphones, in a dynamic (DRR-WSN) paradigm, which could contribute significantly to the resource pool. Intuitively, multiple-owners are involved as resource providers and require different applications. Thus, we address the valuation of resources as they are shared across network owners. We finally present a maximal matching problem of finding the lowest cost for running each application, based on the available resource pool in the vicinity required. Extensive performance evaluation depicts the impact of RR-WSN design on WSN operation and longevity in various scenarios. / Thesis (Ph.D, Computing) -- Queen's University, 2013-08-27 04:44:14.556
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Tracking mobile targets through Wireless Sensor NetworksAlhmiedat, Tareq Ali January 2009 (has links)
In recent years, advances in signal processing have led to small, low power, inexpensive Wireless Sensor Network (WSN). The signal processing in WSN is different from the traditional wireless networks in two critical aspects: firstly, the signal processing in WSN is performed in a fully distributed manner, unlike in traditional wireless networks; secondly, due to the limited computation capabilities of sensor networks, it is essential to develop an energy and bandwidth efficient signal processing algorithms. Target localisation and tracking problems in WSNs have received considerable attention recently, driven by the necessity to achieve higher localisation accuracy, lower cost, and the smallest form factor. Received Signal Strength (RSS) based localisation techniques are at the forefront of tracking research applications. Since tracking algorithms have been attracting research and development attention recently, prolific literature and a wide range of proposed approaches regarding the topic have emerged. This thesis is devoted to discussing the existing WSN-based localisation and tracking approaches. This thesis includes five studies. The first study leads to the design and implementation of a triangulation-based localisation approach using RSS technique for indoor tracking applications. The presented work achieves low localisation error in complex environments by predicting the environmental characteristics among beacon nodes. The second study concentrates on investigating a fingerprinting localisation method for indoor tracking applications. The proposed approach offers reasonable localisation accuracy while requiring a short period of offline computation time. The third study focuses on designing and implementing a decentralised tracking approach for tracking multiple mobile targets with low resource requirements. Despite the interest in target tracking and localisation issues, there are few systems deployed using ZigBee network standard, and no tracking system has used the full features of the ZigBee network standard. Tracking through the ZigBee is a challenging task when the density of router and end-device nodes is low, due to the limited communication capabilities of end-device nodes. The fourth study focuses on developing and designing a practical ZigBee-based tracking approach. To save energy, different strategies were adopted. The fifth study outlines designing and implementing an energy-efficient approach for tracking applications. This study consists of two main approaches: a data aggregation approach, proposed and implemented in order to reduce the total number of messages transmitted over the network; and a prediction approach, deployed to increase the lifetime of the WSN. For evaluation purposes, two environmental models were used in this thesis: firstly, real experiments, in which the proposed approaches were implemented on real sensor nodes, to test the validity for the proposed approaches; secondly, simulation experiments, in which NS-2 was used to evaluate the power-consumption issues of the two approaches proposed in this thesis.
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Uticaj bežične senzorske tehnologije na upravljanje montažnim sistemima / Impact of wireless sensor technology on control of assembly systemsGogolak Laslo 26 June 2014 (has links)
<p>U doktorskoj disertaciji obrađen je problem upravljanja montažnim<br />sistemima pomoću bežične senzorske tehnologije u cilju poboljšanja<br />efikasnosti proizvodnje i poboljšanja kvaliteta proizvoda. U okviru<br />ove disertacije je razvijen model bežičnog upravljačkog sistema za<br />upravljanje i nadzor industrijskih procesa. Glavni cilj istraživanja<br />je razvoj integrisanog sistema za praćenje pozicije radnog predmeta i<br />praćenje okolnosti u kojima se radni predmet nalazi u montažnim<br />sistemima. Rezultati istraživanja su potvrđeni eksperimentalnim<br />istraživanjem u laboratorijskoj i u realnoj industrijskoj sredini.</p> / <p>The dissertation deals with the problem of monitoring and controlling<br />industrial assembly lines by wireless sensor technology with the aim of<br />improving the efficiency of production and the quality of the product. A model<br />of a wireless controlling system has been developed for monitoring and<br />controlling industrial processes. The main focus of the study is the<br />development of an integrated system for monitoring the position of the<br />product and the influences on the product in the assembly lines. The results<br />are confirmed by experiments in a laboratory and real industrial environment.</p>
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VHF & UHF energy harvesting radio system physical and MAC layer considerations / VHF and UHF energy harvesting radio system physical and MAC layer considerationsZhang, Xiaohu January 1900 (has links)
Master of Science / Department of Electrical and Computer Engineering / William B. Kuhn / Wireless Sensor Network industrial and civilian applications have been moved closer to us since they were originally developed for defense applications. They have been or will be widely used in industrial process monitoring and control, earth quake monitoring, healthcare applications, construction health monitoring, home automation, traffic control, and space exploration. The IEEE802.15.4 standard defines the PHY and MAC layers for low power wireless sensor networks. However, applications and research of wireless sensor networking are centered on battery powered devices. To remove the battery from the system is the ultimate goal of this research by using Energy Harvesting technology, which will largely reduce the wireless sensor network maintenance cost, increase the option open to application environments and push the speed of wireless sensor network industrialization.
This thesis tackles the problem of RF link budget and PHY layer design for Energy Harvesting Wireless Sensor Network Nodes, through a modification to PHY/MAC layers. To this end, a prototype of energy harvesting radio is developed that hinges on burst-communication and solar cell energy harvesting techniques. The choice of operating frequency is considered relative to transmission range, antenna technology and RF link budget, and quantified by propagation measurements at four unlicensed frequencies in the VHF through UHF spectrums. A short preamble, PHY payload protocol frame structure and synchronization method are also proposed in order to support long sleep period duty cycle necessary in Energy Harvesting Radio systems. Some related work has recently begun under a standardization effort known as 802.15.4f. It is hoped that this thesis will contribute to this effort.
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Redes de sensores sem fio na coleta de dados fisiológicos de bovinos para aplicações na zootecnia de precisão / Wireless sensor networks technology applied to bovine physiological data acquisition for precision animal productionArce, Aldo Ivan Céspedes 22 February 2008 (has links)
Este trabalho mostra a aplicação das redes de sensores sem fio na monitoração de variáveis fisiológicas de bovinos. A necessidade de experimentar técnicas de coleta de dados, que causem menos perturbações no comportamento natural dos animais de interesse da zootecnia de precisão, foi a principal motivação deste trabalho. Para testar a aplicabilidade da tecnologia das redes de sensores sem fio neste campo, foi desenvolvida uma infra-estrutura, utilizando técnicas de instrumentação eletrônica e comunicação sem fio via rádio-freqüência. A rede foi projetada com o protocolo floating base sensor network (FBSN) que implementa uma topologia adhoc com escolha aleatória dos nós. Os protótipos desenvolvidos foram utilizados para efetuar coletas de sinais cerebrais e temperaturas corporais de bovinos adultos. Foram desenvolvidos também os softwares embarcados e de supervisão e um simulador de deslocamento bovino, que foi utilizado como ferramenta de auxílio no projeto da infra-estrutura de monitoramento implementada. O consumo das fontes de energia e a relação custo-beneficio do sistema foram os principais itens avaliados. Os resultados obtidos mostraram que é possível utilizar redes de sensores sem fio como técnicas eficientes para coleta de dados fisiológicos de bovinos. / This work presents an application of wireless sensor networks technology used for bovine physiological variables monitoring. The main stimulus of this work was the precision animal production researcher\'s interest in developing and testing new techniques that could allow data acquisition with less interference in animal behavior. In order to test the feasibility of the wireless sensor network technology in this area, an infrastructure was developed using electronic instrumentation and radio frequency wireless communication techniques. The network was projected to support the floating base sensor network protocol that is a special kind of adhoc topology with randomic selection of path nodes. The developed prototypes were used to acquire brain electrical activity and body temperature from bovines. The development of supervisor and embedded software and a bovine\'s displacement simulator tool was also described here. The energy consumption and the cost-benefit relationship of the network nodes were the main evaluated features. The results obtained prove that the wireless sensor networks can be considered as an efficient technique to be used to acquire bovine\'s physiological data.
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Um sistema de alerta para o monitoramento remoto do consumo de energia usando redes de sensores sem fio / An alert for remote monitoring of energy consumption using wireless sensor networksRocha Filho, Geraldo Pereira 06 June 2014 (has links)
Determinar quais são os aparelhos eletrônicos de uma residência que possuem maior influência na conta de luz não é tarefa trivial. As Redes de Sensores Sem Fios (RSSF) auxiliam os usuários nessa tarefa, permitindo descobrir se há algum tipo de desperdício no ambiente monitorado e assim, auxiliá-los a fazer as devidas correções. Por isso, é fundamental usar nas smart grids métodos que detectam novidades, também conhecido como anomalias , de forma individual e autônoma, para os usuários quando algo anômalo surge no consumo de energia dos equipamentos eletrônicos. Tais anomalias podem surgir, por exemplo, quando um equipamento consome energia acima do esperado, o que pode indicar um defeito. Nesse contexto, este trabalho propõe um método inteligente, nomeado como Novelty Detection Power Meter (NodePM), para detectar as novidades no consumo de energia dos equipamentos eletrônicos monitorados por uma smart grid. O NodePM detecta as novidades considerando a entropia de cada equipamento monitorado, a qual é calculada com base em um modelo de cadeia de markov que é gerado através de um algoritmo de aprendizado de máquina. Para tanto, o NodePM é integrado a uma plataforma de monitoramento remoto de consumo de energia, que consiste de uma RSSF associada a uma aplicação em nuvem. Para validar o desempenho do NodePM foram feitos experimentos utilizando a análise de variância e testes paramétricos e não-paramétricos. Os resultados de tais experimentos, obtidos mediante a análise estatística, evidenciou a viabilidade do NodePM na plataforma desenvolvida / It is not a simple task to determine which pieces of elevtronic equipment have the greatest influence on the electricity bill. The Wireless Sensor Networks (WSN) assist users in this task, allowing to discover if there is any type of a waste in a monitored environment and thus, help them to take proper actions. Hence, it is of crucial importance to use intelligent methods in the smart grids for a novelty detection and to inform the users in an individual and autonomous way when some anomaly has occurred in the energy consumption of electronic equipment. These anomalies can arise, for instance, when a piece of equipment consumes more energy than expected. In this context, we propose an intelligent method, named the Novelty Detection Power Meter (NodePM), to detect the novelties in the energy consumption of electonic equipment monitored by a smart grid. The NodePM detects the novelties considering the entropy of each device monitored, which is calculed based on a Markov chain model that is generated through a machine learning algorithm. For this end, the NodePM is integrated into a platform for the remote monitoring of energy consumption, which consists of a WSN associated with a cloud application. To validate the performance of the NodePM, experiments were done using analysis of variance and parametric and non-parametric tests. The result of these tests, which were obtained from a statistical analysis, provided evidence of the feasibility of the NodePM in the platform that was developed
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