41 research outputs found
Efficiency and Sustainability of the Distributed Renewable Hybrid Power Systems Based on the Energy Internet, Blockchain Technology and Smart Contracts-Volume II
The climate changes that are becoming visible today are a challenge for the global research community. In this context, renewable energy sources, fuel cell systems, and other energy generating sources must be optimally combined and connected to the grid system using advanced energy transaction methods. As this reprint presents the latest solutions in the implementation of fuel cell and renewable energy in mobile and stationary applications, such as hybrid and microgrid power systems based on the Energy Internet, Blockchain technology, and smart contracts, we hope that they will be of interest to readers working in the related fields mentioned above
Space shuttle orbiter avionics software. Systems analysis flight software and SDL analysis reports
Results are presented of systems analyses of the avionics software of the space shuttle orbiter
Ultra-Low Power Optical Interface Circuits for Nearly Invisible Wireless Sensor Nodes.
Technological advances in the semiconductor industry and integrated circuit design have resulted in electronic devices that are smaller and cheaper than ever, and yet they are more pervasive and powerful than what could hardly be imagined several decades ago. Nowadays, small hand-held devices such as smartphones have completely reshaped the way people communicate, share information, and get entertained. According to Bell’s Law, the next generation of computers will be cubic-millimeter-scale in volume with more prevalent presence than any other computing platform available today, opening up myriad of new applications.
In this dissertation, a millimeter-scale wireless sensor node for visual sensing applications is proposed, with emphasis on the optical interface circuits that enable wireless optical communication and visual imaging. Visual monitoring and imaging with CMOS image sensors opens up a variety of new applications for wireless sensor nodes, ranging from surveillance to in vivo molecular imaging. In particular, the ability to detect motion can enable intelligent power management through on-demand duty cycling and reduce the data storage requirement. Optical communication provides an ultra-low power method to wirelessly control or transmit data to the sensor node after encapsulation and deployment.
The proposed wireless sensor node is a nearly-invisible, yet a complete system with imaging, optics, two-way wireless communication, CPU, memory, battery and energy harvesting with solar cells. During its ultra-low power motion detection mode, the overall power consumption is merely 304 nW, allowing energy autonomous continuous operation with 10 klux of background lighting. Such complete features in the unprecedented form factor can revolutionize the role of electronics in our future daily lives, taking the “Smart Dust” concept from fiction to reality.PhDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/110399/1/coolkgh_1.pd
Universal Event and Motion Editor for Robots\u27 Theatre
Most of work on motion of mobile robots is to generate plans for avoiding obstacles or perform some meaningful and useful actions. In modern robot theatres and entertainment robots the motions of the robot are scripted and thus the performance or behavior of the robot is always the same. In this work we want to propose a new approach to robot motion generation. We want our robot to behave more like real people. People do not move in mechanical way like robots. When a human is supposed to execute some motion, these motions are similar to one another but always slightly or not so slightly different. We want to reproduce this property based on the introduced by us new concept of probabilistic regular expression, a method to describe sets of interrelated similar actions instead of single actions. Our goal is not only to create motions for humanoid robots that will look more naturally and less mechanically, but also to program robots that will combine basic movements from certain library in many different and partially random ways. While the basic motions were created ahead of time, their combinations are specified in our new language. Although now our method is only for motions and does not take inputs from sensors into account, in future the language can be extended to input/output sequences, thus the robot will be able to adapt the motion in different ways, to some sets of sequences of input stimuli. The inputs will come from sensors, possibly attached to limbs of controlling humans from whom the patterns of motion will be acquired
Energy Harvesting Systems for the Internet of Things with Applications to Smart Agriculture
The Internet of Things is the interconnection of everyday objects to the web, with the purpose of exchanging information to enable smarter actions and potentially make a process more efficient. However, how power is provided and stored in remote sensing applications is still one of the main modern electronics challenges of such technology and can become one of the main constraints to prevent its mass adoption. Energy Harvesting is an emerging technology that can transform energy in the environment into usable energy, among such environmental energy are electromagnetic waves, thermal, solar, kinesthetic transducers, fuel cells, to name a few. Because this technology makes use of the available ambient energy, it has the potential to increase the power readiness for battery-operated electronics and more importantly, it can become the technology that fully powers the next generation of internet-enabled agricultural solutions.
This dissertation centers around the design and development of high-efficient power management systems for AC and DC energy harvesting sources. The proposed architectures not only consider circuits, systems and algorithms that make a more efficient power extraction but also focuses on providing inherent sensing functionalities at no extra system complexity, which in turn not only achieves the goal of extending the battery life of proposed smart sensor applications but also proposes new charge extraction methods to permanently power an electronic device. The work presented in this dissertation demonstrates that energy harvesting, and internet of things devices can be implemented in multiple smart agriculture scenarios by proposing algorithms, circuits and systems capable of performing energy harvesting operations while providing reliable data to the end user. The analysis of the design of such proof-of-concept prototypes are provided in this dissertation along with its implementation and testing. The first part of this dissertation proposes novel algorithms for maximum power extraction and new power measurement techniques. The second part focuses on front-end circuits for AC energy harvesting sources and circuits that can provide sensing capabilities along with energy harvesting operations
Developing Energy Harvest Efficient Strategies with Microbial Fuel Cells
Nowadays, thinking of energetic efficiency is to determine how to decrease consumption
and to reuse resources. This is a major concern when addressing hydric resources. The
consumption of drinking water is seeing an unaffordable growth and, although most of
it is replenished to the environment, the water quality is affected by pollutants and
impurities.
As such, using wastewater, a by-product of our routine and way of life, as resource is an
asset. Even more when thinking about the heightened energy costs of a wastewater
treatment station.
The hypotheses of this work show how to achieve this goal by using microbial fuel cells.
The organic composition of this water increases its energy production potential, where
the bacterial metabolism can be used to, simultaneously, produce energy and help to
clean the water.
This document is divided in 5 chapters. The strategic positioning of the theme happens
in chapter 1. Chapter 2 explains how the main elements of microbial fuel cell technology
can work and determine its operation. In chapter 3, the power management systems used
with microbial fuel cells are presented and discussed, with the identification of
optimization strategies. The second-to-last chapter corresponds to the experimental
results discussion and validation, while focusing improved energy production
efficiencies. The outputs of this chapter pilot the future work analysis on chapter 5,
together with the main conclusions and research trends. The validity and usefulness of
this work is cleared with an application example.Pensar em economia energética é, hoje, considerar soluções para a redução de consumo
e reutilização de recursos. Esta preocupação é importante ao examinar a utilização dos
recursos hídricos. O consumo de água potável está a crescer insustentavelmente e, apesar
de grande parte desse consumo ser restituído ao meio ambiente, a qualidade da água é
afetada por poluentes ou impurezas.
A utilização de água residual, um produto da nossa rotina e qualidade de vida, como um
recurso é, por isso, uma mais valia. É ainda mais evidente ao considerar os elevados
consumos energéticos de uma estação de tratamento de água residual.
As hipóteses abordadas neste trabalho mostram como é possível atingir este objetivo
usando células microbianas de combustível. A composição orgânica desta água faz com
que o seu potencial energético possa ser explorado, usando o metabolismo bacteriano
para produzir energia e, simultaneamente, auxiliar na limpeza da água.
Este documento está dividido em 5 capítulos. O posicionamento do tema ocorre no
capítulo 1. O capítulo 2 observa os principais elementos da tecnologia das células
microbianas de combustível, permitindo compreender o seu funcionamento e conhecer
que variáveis afetam o seu funcionamento. No capítulo 3 são apresentadas as tipologias
de abordagem à gestão energética para esta pilha bacteriológica, discutindo-se as
vantagens e otimizações de cada sistema. O penúltimo capítulo corresponde à exploração
de resultados experimentais e à validação de hipóteses, orientadas para a maior
eficiência energética. Surgem assim recomendações que servirão para guiar os trabalhos
futuros, discutidos no capítulo final. Este, o capítulo 5, conta ainda com a apresentação
das principais conclusões e das tendências de pesquisa. O trabalho termina com um
exemplo de aplicação que solidifica a validade e utilidade da aplicação desta tecnologia
Transient performance simulation of gas turbine engine integrated with fuel and control systems
Two new methods for the simulation of gas turbine fuel systems, one based on
an inter-component volume (ICV) method, and the other based on the iterative
Newton Raphson (NR) method, have been developed in this study. They are able
to simulate the performance behaviour of each of the hydraulic components such
as pumps, valves, metering unit of a fuel system, using physics-based models,
which potentially offer more accurate results compared with those using transfer
functions. A transient performance simulation system has been set up for gas
turbine engines based on an inter-component volume (ICV). A proportional-
integral (PI) control strategy is used for the simulation of engine control systems.
An integrated engine and its control and hydraulic fuel systems has been set up
to investigate their coupling effect during engine transient processes. The
developed simulation methods and the systems have been applied to a model
turbojet and a model turboshaft gas turbine engine to demonstrate the
effectiveness of both two methods. The comparison between the results of
engines with and without the ICV method simulated fuel system models shows
that the delay of the engine transient response due to the inclusion of the fuel
system components and introduced inter-component volumes is noticeable,
although relatively small. The comparison of two developed methods applied to
engine fuel system simulation demonstrate that both methods introduce delay
effect to the engine transient response but the NR method is ahead than the ICV
method due to the omission of inter-component volumes on engine fuel system
simulation. The developed simulation methods are generic and can be applied to
the performance simulation of any other gas turbines and their control and fuel
systems.
A sensitivity analysis of fuel system key parameters that may affect the engine
transient behaviours has also been achieved and represented in this thesis.
Three sets of fuel system key parameters have been introduced to investigate
their sensitivities, which are, the volumes introduced for ICV method applied to
fuel system simulation; the time constants introduced into those first order lags tosimulate the valve movements delay and fuel spray delay effect; and the fuel
system key performance and structural parameters
Applications of Computational Intelligence to Power Systems
In power system operation and control, the basic goal is to provide users with quality electricity power in an economically rational degree for power systems, and to ensure their stability and reliability. However, the increased interconnection and loading of the power system along with deregulation and environmental concerns has brought new challenges for electric power system operation, control, and automation. In the liberalised electricity market, the operation and control of a power system has become a complex process because of the complexity in modelling and uncertainties. Computational intelligence (CI) is a family of modern tools for solving complex problems that are difficult to solve using conventional techniques, as these methods are based on several requirements that may not be true all of the time. Developing solutions with these “learning-based” tools offers the following two major advantages: the development time is much shorter than when using more traditional approaches, and the systems are very robust, being relatively insensitive to noisy and/or missing data/information, known as uncertainty
A Novel Energy Harvesting Aware Routing Protocol for Underwater Wireless Sensor Networks
Underwater wireless sensor networks (UWSNs) have the potential to empower smart ocean applications. However, the widespread use of UWSN applications has been limited due to the many daunting challenges incurred in underwater wireless acoustic communication. Moreover, underwater wireless communication is energy-hungry, which confines UWSN deployment to small-scale due to the risks and costs of missions for at sea replacement of the nodes' batteries. The energy harvesting capability of underwater sensor nodes is an important characteristic that has been overlooked in the literature. In this thesis, we study the data routing process in UWSNs with energy harvesting capabilities. We proposed a novel opportunistic routing protocol, named RELOR, that is the first in the literature to consider the energy harvesting capability of underwater sensor nodes during routing decisions. RELOR implements a learning framework for the best selection of the forwarder nodes based on the observed environment conditions. We conduct extensive simulations to compare the performance of the proposed protocol to the state-of-the-art solution. Obtained results show that RELOR outperforms the related work in terms of packet delivery ratio, end-to-end latency, and nodes’ energy consumption