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1
Roussel, Stephane M. "Sensor Integration for Low-Cost Crash Avoidance." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/184.
Повний текст джерелаАнотація:
This report is a summary of the development of sensor integration for low-cost crash avoidance for over-land commercial trucks. The goal of the project was to build and test a system composed of low-cost commercially available sensors arranged on a truck trailer to monitor the environment around the truck. The system combines the data from each sensor to increase the reliability of the sensor using a probabilistic data fusion approach. A combination of ultrasonic and magnetoresistive sensors was used in this study. In addition, Radar and digital imaging were investigated as reference signals and possible candidates for additional sensor integration. However, the primary focus of this work is the integration of the ultrasonic and magnetoresistive sensors.
During the investigation the individual sensors were evaluated for their use in the system. This included communication with vendors and lab and field testing. In addition, the sensors were modeled using an analytical mathematical model to help understand and predict the sensor behavior. Next, an algorithm was developed to fuse the data from the individual sensors. A probabilistic approach was used based on Bayesian filtering with a prediction-correction algorithm. Sensor fusion was implemented using joint a probability algorithm. The output of the system is a prediction of the likelihood of the presence of a vehicle in a given region near the host truck trailer. The algorithm was demonstrated on the fusion of an ultrasonic sensor and a magnetic sensor. Testing was conducted using both a light pickup truck and also with a class 8 truck. Various scenarios were evaluated to determine the system performance. These included vehicles passing the host truck from behind and the host truck passing vehicles. Also scenarios were included to test the system at distinguishing other vehicles from objects that are not vehicles such as sign posts, walls or railroads that could produce electronic signals similar to those of vehicles and confuse the system. The test results indicate that the system was successful at predicting the presence and absence of vehicles and also successful at eliminating false positives from objects that are not vehicles with overall accuracy ranging from 90 to 100% depending on the scenario. Some additional improvements in the performance are expected with future improvements in the algorithm discussed in the report.
The report includes a discussion of the mapping of the algorithm output with the implementation of current and future safety and crash avoidance technologies based on the level of confidence of the algorithm output and the seriousness of the impending crash scenario. For example, irreversible countermeasures such as firing an airbag or engaging the brakes should only be initiated if the confidence of the signal is very high, while reversible countermeasures such as warnings to the driver or nearby vehicles can be initiated with a relatively lower confidence.
The results indicate that the system shows good potential as a low cost alternative to competing systems which require multiple, high cost sensors. Truck fleet operators will likely adopt technology only if the costs are justified by reduced damage and insurance costs, therefore developing an effective crash avoidance system at a low cost is required for the technology to be adopted on a large scale.
2
Jacobs, M. J. "A low cost, high precision star sensor." Thesis, Stellenbosch : University of Stellenbosch, 1995. http://hdl.handle.net/10019.1/4659.
Повний текст джерелаАнотація:
Thesis (MEng (Electrical and Electronic Engineering))--University of Stellenbosch, 1995.189 leaves single sided printed, preliminary pages and numbered pages 1-126. Includes bibliography, list of appendixes, figures, notation and symbols. Digitized at 300 dpi (OCR), using a Bizhub 250 Scanner.
ENGLISH ABSTRACT: The Sunsat microsatellite is being developed at the University of Stellenbosch. It is equipped with a high resolution earth imager which requires a sophisticated attitude determination and control system. Precise control of the satellite is impossible without high precision attitude sensors. The most accurate attitude sensor presently used by satellites is the star sensor. The aim 'of this thesis is to develop a low cost, high precision star sensor for the Sunsat microsatellite. The development included the selection of electronic and optical hardware followed by the design, construction and testing of the sensor. Software algorithms were developed and programmed to control the imager, extract stars from images and match the observed constellations to a star catalogue. A set of matching observed and reference vectors are passed to the attitude determination and control system which calculates the three axis orientation of the satellite.
AFRIKAANSE OPSOMMING: Die Sunsat mikrosatelliet word tans by die Universiteit van Stellenbosch ontwikkel. Dit is toegerus met 'n hoeresolusie aardwaarnemingskamera en vereis 'n gevorderde orientasiebepaling-en beheerstelsel. Presiese beheer is onmoontlik sonder akkurate sensore. 'n Stersensor is die mees akkurate tipe sensor waarmee satelliete tans toegerus word. Die doelwit van hierdie tesis is die ontwikkeling van 'n hoe resolusie, laekoste stersensor vir die Sunsat mikrosatelliet. Die ontwikkeling behels die seleksie van elektroniese en optiese apparatuur wat gevolg is deur die ontwerp, opbou en toets van die sensor. Programmatuur algoritrnes is ontwerp om die kamera te beheer, sterre in fotos te herken en waargenome konstellasies in die sterkatalogus te vind. 'n Stel waargenome en verwysingsvektore stel die orientasiebepaling-en beheerstelsel in staat om die orientasie van die satelliet te bereken.
3
Abbas, Syed Farhat. "Development of a low cost shock pressure sensor." Ohio : Ohio University, 1988. http://www.ohiolink.edu/etd/view.cgi?ohiou1182538469.
Повний текст джерела
4
Rockey, Chad A. "Low-cost Sensor Package for Smart Wheelchair Obstacle Avoidance." Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1327595053.
Повний текст джерела
5
Yap, Teddy. "Mobile robot navigation with low-cost sensors." Diss., [Riverside, Calif.] : University of California, Riverside, 2009. http://proquest.umi.com/pqdweb?index=0&did=1957353711&SrchMode=2&sid=1&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1268419222&clientId=48051.
Повний текст джерелаАнотація:
Thesis (Ph. D.)--University of California, Riverside, 2009.Includes abstract. Title from first page of PDF file (viewed March 12, 2010). Available via ProQuest Digital Dissertations. Includes bibliographical references (p. 138-144). Also issued in print.
6
Reed, Ahren Alexander. "Detecting Suspicious Behavior With Low-cost Sensors." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/655.
Повний текст джерелаАнотація:
A proof of concept is created that demonstrates how low-cost sensors and a simple software solution can be used to proactively detect IED placement. The main goal is to detect suspicious behavior; Specifically we derive requirements that loitering, meandering, improper location and object placement shall be detected. Current methods being used to detect Improvised Explosive Devices (IEDs) are costly in terms of equipment and risk to life, and many are retroactive; IED detection occurs long after explosives are placed. A prototype system is explored with the quality attributes of being low-cost, proactive and using simple software methods. A wireless sensor network of simple sensors may alert authorities to people in the act of placing IEDs. Previous work with Crossbow Motes showed that a network of infrared motion sensors can be used to detect loitering. In this prototype nine other sensors are reverse engineered to determine their true operating specifications. Then a prototype sensor network is developed to explore which low-cost sensors can be used to detect suspicious behavior. The results indicate that five low-cost sensors are effective in detecting suspicious behavior: infrared motion, infrared distance, light, force sensors and pressure sensors meet our requirements.
7
Woo, Heechul. "The selective low cost gas sensor based on functionalized graphene." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLX050/document.
Повний текст джерелаАнотація:
Les progrès récents dans les nanomatériaux présentent un fort potentiel pour la réalisation de capteurs de gaz avec de nombreux avantages tels que : la grande sensibilité de détection de molécule unique, le faible coût et la faible consommation d'énergie. Le graphène, isolé en 2004, est l'un des meilleurs candidats prometteurs pour le développement de futurs nanocapteurs en raison de sa structure à deux dimensions, sa conductivité élevée et sa grande surface spécifique. Chaque atome de la monocouche de graphène peut être considéré comme un atome de surface, capable d'interagir même avec une seule molécule de l'espèce gazeuse ou de vapeur cible, ce qui conduit finalement à un capteur ultrasensible.Dans cette thèse, des composants à base de graphène ont été fabriqués et caractérisés. Les films de graphène ont été synthétisés par dépôt chimique à phase vapeur (CVD) sur des substrats de verre. La spectroscopie Raman a été utilisée pour analyser la qualité et le nombre de couches de graphène. La microscope à force atomique (AFM) et la microscopie électronique à balayage (MEB) ont été également réalisées pour analyser la qualité du graphène. Après la caractérisation de couches de graphène, des dispositifs résistifs à base de graphène ont été fabriquées : quatre électrodes identiques ont été évaporées thermiquement et directement sur le film de graphène comme des électrodes métalliques. La caractérisation électrique a été réalisée à l'aide de Keithley-4200.La réponse de dispositif Intrinsèque a été étudiée sous différents conditions (pression, humidité, exposition à la lumière). Le dispositif a été fonctionnalisé de manière non covalente avec le complexe organométallique (Ru (II) trisbipyridine) et son effet sous exposition à la lumière a été étudié. La réponse de dispositif était reproductible même après de nombreux cycles en présence et en absence de la lumière. Les approches théoriques et expérimentales ainsi que les résultats obtenus au cours de cette thèse ouvrent un moyen de comprendre et de fabriquer des futurs dispositifs de détection de gaz à base du graphène fonctionnalisé de manière non covalenteRecent advances in nanomaterials provided a strong potential to create a gas sensor with many advantages such as high sensitivity of single molecule detection, low cost, and low power consumption. Graphene, isolated in 2004, is one of the best promising candidate for the future development of nanosensors applications because of its atom-thick, two-dimensional structures, high conductivity, and large specific surface areas. Every atom of a monolayer graphene can be considered as a surface atom, capable of interacting even with a single molecule of the target gas or vapor species, which eventually results in the ultrasensitive sensor response.In this thesis work, graphene films were synthesized by Chemical Vapor Deposition (CVD) on the glass substrate. Raman spectroscopy was used to analyze the quality and number of layers of graphene. Atomic Force Microscope (AFM) and Scanning Electron Microscopy (SEM) were also performed to analyze the quality of graphene. After the characterization of graphene films, graphene based resistive devices (four identical electrodes are thermally evaporated directly onto the graphene film as metal electrodes) were fabricated. The electrical characterization has been carried out using Keithley-4200.Intrinsic device response was studied with different external condition changes (pressure, humidity, light illumination). The device was non-covalently functionalized with organometallic complex (Ru(II) trisbipyridine) and the its light exposure response was studied. The observed device response was reproducible and similar after many cycles of on and off operations. The theoretical and experimental approaches and the results obtained during the thesis are opening up a way to understand and fabricate future gas sensing devices based on the non-covalentely functionalized graphene
8
Bouffard, Joshua Lee. "An Alternative Sensor Fusion Method For Object Orientation Using Low-Cost Mems Inertial Sensors." ScholarWorks @ UVM, 2016. https://scholarworks.uvm.edu/graddis/537.
Повний текст джерелаАнотація:
This thesis develops an alternative sensor fusion approach for object orientation using low-cost MEMS inertial sensors. The alternative approach focuses on the unique challenges of small UAVs. Such challenges include the vibrational induced noise onto the accelerometer and bias offset errors of the rate gyroscope. To overcome these challenges, a sensor fusion algorithm combines the measured data from the accelerometer and rate gyroscope to achieve a single output free from vibrational noise and bias offset errors.
One of the most prevalent sensor fusion algorithms used for orientation estimation is the Extended Kalman filter (EKF). The EKF filter performs the fusion process by first creating the process model using the nonlinear equations of motion and then establishing a measurement model. With the process and measurement models established, the filter operates by propagating the mean and covariance of the states through time.
The success of EKF relies on the ability to establish a representative process and measurement model of the system. In most applications, the EKF measurement model utilizes the accelerometer and GPS-derived accelerations to determine an estimate of the orientation. However, if the GPS-derived accelerations are not available then the measurement model becomes less reliable when subjected to harsh vibrational environments. This situation led to the alternative approach, which focuses on the correlation between the rate gyroscope and accelerometer-derived angle. The correlation between the two sensors then determines how much the algorithm will use one sensor over the other. The result is a measurement that does not suffer from the vibrational noise or from bias offset errors.
9
Tozzi, Michael Jay. "Development and implementation of low cost mobile sensor platforms within a wireless sensor network." Thesis, Monterey, California. Naval Postgraduate School, 2010. http://hdl.handle.net/10945/5232.
Повний текст джерелаАнотація:
Approved for public release; distribution is unlimitedSensor networks are used throughout the government and industry for a wide variety of purposes. Mobile Sensor Platforms (MSPs), from surface combatant vessels to unmanned aerial vehicles, have been integrated into these sensor networks since their inception. Unmanned MSPs currently used in sensor networks have two major drawbacks: They are extremely expensive and they require the control of a human operator. Remote controlled unmanned systems currently do not eliminate risk to personnel entirely, because they are typically too expensive to be considered expendable. If these standard unmanned systems are downed in a hostile environment, their recovery is often attempted by personnel on the ground; thus, still risking human lives. The military is exploring the use of low-cost unmanned MSPs to eliminate the need to risk personnel in their recovery. One of the greatest expenses in the life cycle of any system is operator cost. To reduce or eliminate operator cost, a platform must be autonomous. Though algorithms exist for adding autonomous capabilities to a mobile platform, such algorithms are typically designed for robust systems with a great deal of processing power. Low-cost systems are typically limited in capability by a low-processing power CPU. For this reason, small footprint alternatives to existing autonomous control algorithms must be developed to truly implement a low-cost MSP. This thesis applies the systems engineering process to developing a generic system solution for the need of a low-cost MSP, with concept of operations, external systems diagram, generic requirements, functional architecture and decompositions developed. The proposed generic system solution is then further designed in a scoped environment and implemented as a proof of concept prototype.
10
Alzebda, Said Anwar. "Low-cost oscillating sensor for ultrasonic testing and monitoring of liquids." Thesis, University of Nottingham, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.546599.
Повний текст джерела
11
Jones, Samuel M. "Evaluation of a low-cost aerosol sensor to assess occupational exposures." Thesis, University of Iowa, 2015. https://ir.uiowa.edu/etd/1858.
Повний текст джерелаАнотація:
A Dylos DC1100 was evaluated to: 1. Establish relationship between low-cost DC1100 and higher-cost pDR 1200; 2. Develop a method to convert DC1100 particle number into mass concentration to compare with respirable and inhalable mass references.
A Dylos DC1100 was deployed in a swine CAFO, along with a pDR-1200 and filter set to collect respirable and inhalable particles. Deployment was conducted from December 2013 through February 2014 in 24 hour intervals. The pDR-1200 and respirable mass concentration was used to convert the DC1100 particle count to mass concentration. Two methods of conversion were used, physical property method (Method 1) and regression method (Method 2).
Direct measurements from the DC1100 and pDR-1200 had a coefficient of determination (R2) of 0.85. DC1100 particle number were converted to mass concentration using Method 1 and Method 2, the coefficient of determination (R2) was 0.72 and 0.73, respectively compared to pDR-1200. The slope of the best-fit line was 1.01 for Method 1 and 0.70 for Method 2. When the DC1100 daily averages were compared to respirable mass, the physical property method had an R2 of 0.64 and a slope of 1.10. Regression method had an R2 of 0.62 and a slope of 0.80. Both methods underestimated inhalable mass concentrations with slopes < 0.13.
The Dylos DC1100 can be used to estimate respirable mass concentrations within a CAFO. Using expensive dust monitors to correct the number of particles into a mass concentration is needed to establish a correction factor for the DC1100. Using these methods, correction factors can be determine for many occupational environment, with the physical property method being preferred over the regression method.
12
Yoo, Jin Jung D. "Performance evaluation of a low cost processor with wireless connectivity." Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/4269.
Повний текст джерелаАнотація:
Thesis (M.S.)--University of Missouri-Columbia, 2005.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (July 17, 2006) Includes bibliographical references.
13
Manso, Marco António Azinheira Morais Lourenço. "Design and prototyping of a network-enabled low-cost low-power seismic sensor monitoring system." Doctoral thesis, Universidade de Évora, 2021. http://hdl.handle.net/10174/30827.
Повний текст джерелаАнотація:
Esta tese explora recentes desenvolvimentos em tecnologias de informação, comunicações e
sensores no campo da sismologia. A tese aborda o potencial das redes de monitorização
sísmica de elevada densidade na melhoria da resolução da actividade sísmica observada e,
consequentemente, na melhor compreensão dos processos físicos que estão na base da
ocorrência de terramotos.
A tese argumenta que a tecnologia de sistemas de microelectromecânica (MEMS), usada na
produção de acelerómetros de pequena dimensão, tem aplicabilidade e elevado potencial no
domínio da sismologia. Acelerómetros MEMS já facilitaram a instalação de redes sísmicas de
elevada densidade com superior resolução espacial pela Universidade da Califórnia (Rede
Sísmica Comunitária) e pela Universidade de Évora (Rede Sísmica de Sensores do Alentejo),
esta última ainda em fase de instalação.
Neste contexto, a tese descreve o trabalho conduzido no desenho e desenvolvimento de
sistemas de sensores baseados em acelerómetros MEMS. Este trabalho inclui a
conceptualização de componentes de arquitectura usados para a implementação de quatro
protótipos. Adicionalmente, foram também desenvolvidos os componentes necessários para a
operação e gestão da rede de sensores, que inclui servidores dedicados a operar software
especificamente desenvolvido neste trabalho.
A tese descreve também a instalação e avaliação de protótipos, usando como base de
comparação uma estação sísmica de elevado desempenho, recorrendo inclusivamente à
actividade sísmica resultante de dois eventos sísmicos.
A tese conclui que a arquitectura conceptualizada para o sistema sensor e para a rede de
sensores demonstrou ser eficaz. Adicionalmente, embora a tecnologia MEMS seja promissora,
ainda exibe limitações que limitam a sua aplicabilidade no domínio da sismologia,
especificamente na observação de eventos sísmicos moderados e fortes. Conclui-se também
que a instalação de acelerómetros MEMS em conjunto com sismómetros pode trazer benefícios
na observação de actividade sísmica. Espera-se também que futuras gerações de acelerómetros
MEMS possam ter uma adoção generalizada na sismologia; ABSTRACT:
This thesis exploits advances in information technologies, communications and sensor systems
to the field of seismology. It addresses the potential for high-density networks for seismic
monitoring aiming to improve the resolution of the recorded seismic activity and, consequently,
to improve the understanding of the physical processes that cause earthquakes, as well as to
gather more detailed seismic characterisation of studied regions.
It argues that microelectromechanical systems (MEMS) technology, used to produce small size
accelerometers, has a potential application in seismology. Indeed, MEMS accelerometers have
enabled the deployment of high-density seismic networks capable of monitoring seismic
activity with high spatial resolution, such as CalTech's Community Seismic Network (CSN)
and University of Évora’s SSN-Alentejo, currently in the deployment phase.
In this context, this thesis describes the work conducted to design and develop low-cost seismic
sensor systems, based on low-cost MEMS accelerometers. This work includes the
conceptualisation of the architectural components that were implemented in four prototypes.
Moreover, server-side components, necessary to operate and manage the sensor network, as
well as to provide visualisation tools for users, are also developed and presented.
This work also describes the field deployment and evaluation of selected prototypes, using a
high-performance seismic station as the reference sensor for comparison, based on generated
signals and two recorded seismic events.
It is concluded that the herein conceptualised architecture for the high-dense network and
sensor prototypes has been demonstrated to be effective. Moreover, albeit promising, MEMS
accelerometers still exhibit performance limitations constraining their application in
seismology addressing moderate and strong motion. In addition, MEMS accelerometers
characteristics complement seismometers, thus installing MEMS accelerometers with
seismometers, may provide additional insights concerning seismic activity and seismology in
general. It is also expected that next generation MEMS accelerometers will be capable to
compete with traditional seismometers, becoming the de facto technology in seismology.
14
Le, Xuan-Chien. "Improving performance of non-intrusive load monitoring with low-cost sensor networks." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S019/document.
Повний текст джерелаАнотація:
Dans les maisons et bâtiments intelligents, il devient nécessaire de limiter l'intervention humaine sur le système énergétique, afin de fluctuer automatiquement l'énergie consommée par les appareils consommateurs. Pour cela, un système de mesure de la consommation électrique d'équipements est aussi nécessaire et peut être déployé de deux façons : intrusive ou non-intrusive. La première solution consiste à relever la consommation de chaque appareil, ce qui est inenvisageable à une grande échelle pour des raisons pratiques liées à l'entretien et aux coûts. Donc, la solution non-intrusive (NILM pour Non-Intrusive Load Monitoring), qui est capable d'identifier les différents appareils en se basant sur les signatures extraites d'une consommation globale, est plus prometteuse. Le problème le plus difficile des algorithmes NILM est comment discriminer les appareils qui ont la même caractéristique énergétique. Pour surmonter ce problème, dans cette thèse, nous proposons d'utiliser une information externe pour améliorer la performance des algorithmes existants. Les premières informations additionnelles proposées considèrent l'état précédent de chaque appareil comme la probabilité de transition d'état ou la distance de Hamming entre l'état courant et l'état précédent. Ces informations sont utilisées pour sélectionner l'ensemble le plus approprié des dispositifs actifs parmi toutes les combinaisons possibles. Nous résolvons ce problème de minimisation en norme l1 par un algorithme d'exploration exhaustive. Nous proposons également d'utiliser une autre information externe qui est la probabilité de fonctionnement de chaque appareil fournie par un réseau de capteurs sans fil (WSN pour Wireless Sensor Network) déployé dans le bâtiment. Ce système baptisé SmartSense, est différent de la solution intrusive car seul un sous-ensemble de tous les dispositifs est surveillé par les capteurs, ce qui rend le système moins intrusif. Trois approches sont appliquées dans le système SmartSense. La première approche applique une détection de changements de niveau sur le signal global de puissance consommé et les compare avec ceux existants pour identifier les dispositifs correspondants. La deuxième approche vise à résoudre le problème de minimisation en norme l1 avec les algorithmes heuristiques de composition Paréto-algébrique et de programmation dynamique. Les résultats de simulation montrent que la performance des algorithmes proposés augmente significativement avec la probabilité d'opération des dispositifs surveillés par le WSN. Comme il n'y a qu'un sous-ensemble de tous les appareils qui sont surveillés par les capteurs, ceux qui sont sélectionnés doivent satisfaire quelques critères tels qu'un taux d'utilisation élevé ou des confusions dans les signatures sélectionnées avec celles des autresIn smart homes, human intervention in the energy system needs to be eliminated as much as possible and an energy management system is required to automatically fluctuate the power consumption of the electrical devices. To design such system, a load monitoring system is necessary to be deployed in two ways: intrusive or non-intrusive. The intrusive approach requires a high deployment cost and too much technical intervention in the power supply. Therefore, the Non-Intrusive Load Monitoring (NILM) approach, in which the operation of a device can be detected based on the features extracted from the aggregate power consumption, is more promising. The difficulty of any NILM algorithm is the ambiguity among the devices with the same power characteristics. To overcome this challenge, in this thesis, we propose to use an external information to improve the performance of the existing NILM algorithms. The first proposed additional features relate to the previous state of each device such as state transition probability or the Hamming distance between the current state and the previous state. They are used to select the most suitable set of operating devices among all possible combinations when solving the l1-norm minimization problem of NILM by a brute force algorithm. Besides, we also propose to use another external feature that is the operating probability of each device provided by an additional Wireless Sensor Network (WSN). Different from the intrusive load monitoring, in this so-called SmartSense system, only a subset of all devices is monitored by the sensors, which makes the system quite less intrusive. Two approaches are applied in the SmartSense system. The first approach applies an edge detector to detect the step-changes on the power signal and then compare with the existing library to identify the corresponding devices. Meanwhile, the second approach tries to solve the l1-norm minimization problem in NILM with a compositional Pareto-algebraic heuristic and dynamic programming algorithms. The simulation results show that the performance of the proposed algorithms is significantly improved with the operating probability of the monitored devices provided by the WSN. Because only part of the devices are monitored, the selected ones must satisfy some criteria including high using rate and more confusions on the selected patterns with the others
15
Torres, John C. "Geomagnetic Compensation for Low-Cost Crash Avoidance Project." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/492.
Повний текст джерелаАнотація:
The goal of this work was to compensate for the effects of the Earth’s magnetic field in a vector field magnetic sensor. The magnetic sensor is a part of a low-cost crash avoidance system by Stephane Roussel where the magnetic sensor was used to detect cars passing when it was mounted to a test vehicle. However, the magnetic sensor’s output voltage varied when it changed orientation with respect to the Earth’s magnetic field. This limited the previous work to only analyze detection rates when the test vehicle travelled a single heading. Since one of the goals of this system is to be low-cost, the proposed solution for geomagnetic compensation will only use a single magnetic sensor and a consumer-grade GPS. Other solutions exist for geomagnetic compensation but use extra sensors and can become costly.
In order to progress the development of this project into a commercial project, three separate geomagnetic compensation algorithms and a calibration procedure were developed. The calibration procedure compensated for the local magnetic field when the magnetic sensor was mounted to the test vehicle and allowed for consistent magnetic sensor voltage output regardless of the type of test vehicle.
The first algorithm, Compensation Scheme 1 (CS1), characterized the local geomagnetic field with a mathematical function from field calibration data. The GPS heading was used as the input and the output is the voltage level of the Earth’s magnetic field. The second algorithm, Compensation Scheme 1.5, used a mathematical model of the Earth’s magnetic field using the International Geomagnetic Reference Field. An algorithm was developed to take GPS coordinates as an input and output the voltage contributed by the mathematical representation of the Earth’s magnetic field. The output voltages from CS1 and CS1.5 were subtracted from the calibrated magnetic sensor data. The third algorithm, Compensation Scheme 2 (CS2), used a high pass filter to compensate for changes of orientation of the magnetic sensor. All three algorithms were successful in compensating for the geomagnetic field and vehicle detection in multiple car headings was possible.
Since the goal of the magnetic sensor is to detect vehicles, vehicle detection rates were used to evaluate the effectiveness of the algorithms. The individual algorithms had limitations when used to detect passing cars. Through testing, it was found that CS1 and CS1.5 algorithms were suitable to detect vehicles while stopped in traffic while the CS2 algorithm was suitable vehicle detection while the test vehicle is moving.
In order to compensate for the limitations of the individual algorithms, a fused algorithm was developed that used a combination of CS1 and CS2 or CS1.5 and CS2. The vehicle speed was used in order to determine which algorithm to use in order to detect cars. Although the goal of this project is not vehicle detection, the rate of successful vehicle detection was used in order to evaluate the algorithms.
The evaluation of the fused algorithm demonstrated the value of using CS1 and CS1.5 to detect vehicles when stopped in traffic, which CS2 algorithm cannot do. For a study conducted in traffic, using the fused algorithm increased vehicle detection rates by 51%-62% from using the CS2 algorithm alone.
Since this work successfully compensated for geomagnetic effects of the magnetic sensor, the low-cost crash avoidance system can be further developed since it is no longer limited to driving in a single direction. Other projects that experience unwanted geomagnetic effects in their projects can also implement the knowledge and solutions used in this work.
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Garrido, Joana Rodrigues. "TURF: a low cost solution for tracking firemen in urban fires." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14663.
Повний текст джерелаАнотація:
Mestrado em Engenharia Eletrónica e TelecomunicaçõesWhen in critical emergency scenarios, first responders are submitted to highly stressful and risky situations. In order to help them dealing with these conditions, the VitalResponder project started and is now capable of continuously monitor the vital signs of firemen with wearable technologies. This provides to the chief of operations the capability to evaluate the health conditions of his firefighters and react according to their needs. The localization of firemen is an important factor when dealing with urban fires. Due to low visibility and difficult communication conditions, is essential for each fireman to be aware of his colleagues’ whereabouts for organization and, in case of need, rescue matters. The idea behind this dissertation is to build a simple and low cost tracking system, embedded in the VitalResponder wearable technology, which can give information about the presence of a fireman or a wall and its distance. The simplest answer found to this problem was sensor fusion using an infrared sensor, to distinguish a wall from a fireman, and an ultrasound sensor, to provide the distance to the obstacle/colleague.
Em cenários críticos de emergência, as equipas de resposta são submetidas a situações de stress e risco extremamente elevados. Para os ajudar a reagir, deu-se início ao projeto VitalResponder que é atualmente capaz de monitorizar continuamente os sinais vitais dos bombeiros devido à tecnologia embutida nos seus fatos. Este sistema fornece ao comandante de operações a capacidade de avaliar as condições de saúde dos seus bombeiros e agir de acordo com as suas necessidades. A localização de bombeiros é um fator muito importante em situações de incêndios urbanos. Devido às fracas condições de visibilidade e comunicação, é essencial que cada bombeiro tenha noção da posição dos seus colegas por questões de organização e salvamento. O objetivo desta dissertação é construir um sistema simples e de baixo custo, que será incorporado no projeto VitalResponder, e fornecerá informações acerca da presença de um bombeiro ou uma parede e a sua respetiva distância. A solução mais simples para este problema é utilizar fusão sensorial de um sensor infravermelho, para distinguir uma parede de um bombeiro, e um sensor de ultrassom, para medir a distância ao obstáculo/colega.
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Zhao, Yueming. "Key Technologies in Low-cost Integrated Vehicle Navigation Systems." Doctoral thesis, KTH, Geodesi och geoinformatik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-131420.
Повний текст джерелаАнотація:
Vehicle navigation systems incorporate on-board sensors/signal receivers and provide necessary positioning and guidance information for land, marine, airborne and space vehicles. Among different navigation solutions, the Global Positioning System (GPS) and an Inertial Navigation System (INS) are two basic navigation systems. Due to their complementary characters in many aspects, a GPS/INS integrated navigation system has been a hot research topic in recent decades. Both advantages and disadvantages of each individual system and their combination are analysed in this thesis. The Micro Electrical Mechanical Sensors (MEMS) successfully solved the problems of price, size and weight with traditional INS, and hence are widely applied in GPS/INS integrated systems. The main problem of MEMS is the large sensor errors, which rapidly degrade the navigation performance in an exponential speed. By means of different methods, such as autoregressive model, Gauss-Markov process, Power Spectral Density and Allan Variance, we analyse the stochastic errors within the MEMS sensors. The test results show that different methods give similar estimates of stochastic error sources. An equivalent model of coloured noise components (random walk, bias instability and ramp noise) is given. Three levels of GPS/IMU integration structures, i.e. loose, tight and ultra-tight GPS/IMU navigation, are introduced with a brief analysis of each character. The loose integration principles are presented with detailed equations as well as the INS navigation principles. The Extended Kalman Filter (EKF) is introduced as the data fusion algorithm, which is the core of the whole navigation system. Based on the system model, we show the propagation of position standard errors with the tight integration structure under different scenarios. Even less than 4 observable GNSS satellites can contribute to the integrated system, especially for the orientation errors. A real test with loose integration is carried out, and the EKF performance is analysed in detail. Since the GPS receivers are normally working with a digital map, the map matching principle and its link-choosing problem are briefly introduced. This problem is proposed to be solved by the lane detection from real-time images. The procedures for the lane detection based on image processing are presented. The test on high ways, city streets and pathways are successfully carried out, and analyses with possible solutions are given for some special failure situations. To solve the large error drift of the IMU, we propose to support the IMU orientation with camera motion estimation from image pairs. First the estimation theory and computer vision principles are briefly introduced. Then both point and line matches algorithms are given. Finally the L1-norm estimator with balanced adjustment is proposed to deal with possible mismatches (outliers). Tests and comparisons with the RANSAC algorithm are also presented. For the latest trend of MEMS chip sensors, their industry and market are introduced. To evaluate the MEMS navigation performance, we augment the EKF with an equivalent coloured noise model, and the basic observability analysis is given. A realistic simulated navigation test is carried out with single and multiple MEMS sensors, and a sensor array of 5-10 sensors are recommended according to the test results and analysis. Finally some suggestions for future research are proposed.QC 20131016
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Wei, Danming. "Low-Cost Quartz Crystal Microbalance System Platform Designed for Chemical Nanoparticle." TopSCHOLAR®, 2016. http://digitalcommons.wku.edu/theses/1635.
Повний текст джерелаАнотація:
QCM sensor is a response to a kind of broad spectrum, high sensitivity, and simple structure, low-cost detection device, and particularly its quality as a type of gas sensor is widely used. With the successful oscillation in liquid phase, QCM sensor has been involved in the application analytical chemistry, surface chemistry, biochemistry and environmental monitoring side and many other scientific fields. With sensitive surface film as the sensitive element, AT-cut quartz crystal as energy transducer components by changes of the relationship between mass of surface film and frequency of QCM sensor transduces signals of mass or concentration into output frequency signal of sensor, thus achieve changes of mass or concentration detection. This paper mainly states how to design a low-cost QCM system platform with Arduino microcontroller board based on QCM sensor specific properties. For the oscillator circuit selection and differential frequency circuit design, the shield board has properly matched Arduino Mega2560, then by programming code to make Arduino acquire frequency of QCM sensor in real-time. Meanwhile, the interface and data store are corresponding convenient for real- time observing and data post-processing. By the tests of anhydrous ethanol evaporation, QCM system platform was calibrated and Sauerbrey equation verification. Moreover, this paper studies that photocatalytic degradation processing of Rhodamine B (RB) and methyl orange solution at the Surface of nanocrystalline TiO2 by QCM sensor.
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Duran, Joshua. "Silicon-Based Infrared Photodetectors for Low-Cost Imaging Applications." University of Dayton / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=dayton155653478017603.
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Rivest, Christopher W. (Christopher Warren). "Design and characterization of a low cost dual differential proving ring force sensor utilizing Hall-effect sensors." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/36709.
Повний текст джерелаАнотація:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (leaf 31).
A novel dual differential hall-effect based proving ring force sensor has been designed, manufactured, and tested. Strain gauge based force sensors are among the most common methods of measuring static and dynamic forces, yet they suffer from a wide array of negative attributes including: high cost due to signal amplification instrumentation, high temperature sensitivity, and only moderate dynamic range. The goal of the research herein described was to design and test a low cost, high dynamic range force sensor. Hall-Effect sensors have high bandwidth (>100 kHz), a wide dynamic range, are low in cost (<0.5$), and are ideally suited to dynamic and static force measurements. Proving rings - diametrally loaded hoops of metal, have long been used to measure force yet suffer many setbacks due to their historical designs utilizing mechanical and strain gauge methods of strain detection. A novel nested proving ring flexure has been combined with hall-effect sensors to fulfill the design requirements of a low cost and robust force sensor. Initial data demonstrates that the nested proving ring force sensor herein described is capable of resolving forces of in the range of 0 to 30 Newtons with an accuracy of 0.235 Newtons, all at a potential mass-manufactured cost of U.S. $10.00 per unit.
by Christopher W. Rivest.
S.B.
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Gull, Christopher Johannes. "A novel low- cost chlorophyll fluorescence Sensor for early detection of environmental pollution." Universidade Federal de Viçosa, 2017. http://www.locus.ufv.br/handle/123456789/18061.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
A poluição afeta seriamente todos os organismos vivos, assim como economias que dependem, diretamente ou indiretamente, de recursos naturais. O monitoramento ambiental de estresses das plantas, causadas pelos poluentes, é necessário para antecipar e evitar os efeitos negativos antes que se manifestem como danos visíveis. A ausência de monitoramento constante das plantas resulta em diminuição do crescimento das culturas, danos aos ecossistemas, problemas de saúde, e, no fim das contas, perdas econômicas. Especialmente ao redor das áreas afetadas, como, por exemplo, depósitos de resíduos, mineradoras e indústrias, mas também dentro e ao redor das áreas urbanas, é importante reconhecer os problemas potenciais do meio ambiente que possam surgir por causa das atividades humanas. Entre as consequências estão chuva ácida, contaminação de metais pesados, ozônio superficial, modificações de temperatura, e seca, causando alterações na fisiologia vegetal, especificamente na eficiência fotossintética e conteúdo de clorofila. A medição da eficiência fotossintética das plantas, i.e. vitalidade, usando fluorômetros comerciais tais como aparelhos PAM (modulação de amplitude de pulso), torna-se um desafio, uma vez que custo, complexidade e os métodos de medição tornam difíceis o monitoramento em tempo real. Apesar dos aparelhos possuírem alta precisão, podem meramente fornecer uma medição “instantânea” de áreas pequenas. Assim, torna-se difícil o entendimento da vitalidade e eficiência das plantas em grandes áreas e períodos longos, resultando, muitas vezes, que ações sejam tomadas apenas após mudanças significativas nas plantas e na produtividade. Uma solução para o produtor em áreas impactadas por poluentes poderia ser a obtenção de vários desses aparelhos e empregar trabalhadores dedicados exclusivamente para o monitoramento de saúde das plantas, mas isto é caro e ineficiente. Outra solução seria simplificar os equipamentos de medição, e usar vários deles. De fato, neste trabalho nós nos concentramos na resolução deste problema, reduzindo o custo e a complexidade, e eliminando a necessidade de intervenção humana no processo de medição. Propõe-se um sistema de sensores de fluorescência de clorofila de baixo custo que pode monitorar, simultaneamente e sem fios, várias plantas individuais. Estes sensores foram desenvolvidos, prototipados e construídos do zero para dar precisão razoável, com a capacidade de diferenciar entre plantas submetidas à estresse e sem estresse. Nos casos em que o sistema, o Sensor CFY (rendimento fluorescência da clorofila), não possua alta precisão, o sistema compensa em várias medições simultâneas de uma rede de sensores. Isto é, o protótipo do sensor é, inerentemente, desenvolvido para ser usado em redes sem fio (WSN). Usando duas espécies de plantas, Clusia hilariana e Paspalum densum, foi construído, testado e verificado as nossas metodologias e o nosso protótipo através de uma série de experimentos. Baseado nisso, foram observado resultados significativos quando utilizamos o sensor em uma rede de sensores emulado, usando um sensor único em várias plantas durante um longo período de tempo. Foi possível a discriminação entre plantas nos grupos de estresse e as do controle, assim como a descoberta rápida bem antes de danos se manifestarem nas folhas. Concluímos que é, de fato, possível a detecção da estresse nas plantas utilizando métodos de baixo custo, assim como fazê-lo automaticamente e em tempo real, permitindo a detecção precoce de poluição e fornecendo, por exemplo, tempo suficiente para um produtor resolver os problemas antes de eles se tornarem irreversíveis e dispendiosos.
Pollution seriously affects all living organisms as well as economies directly or indirectly relying on natural growth resources. Monitoring the environment for stresses in plants, caused by pollutants, is necessary in order to anticipate and counteract the adverse effects before they manifest as visible damage. Failure to constantly monitor plants results in decreased crop growth, damage to ecosystems, health-related issues, and, ultimately, economic losses. Especially around affected areas, such as waste deposits, mining activities and factories, but also in and around urban areas, it is important to acknowledge the potential environmental issues that may arise from human activities. Among the consequences we find acid rain, heavy metal contamination, surface ozone, changes in temperature, and drought, contributing to alterations in plant physiology, specifically chlorophyll content and photosynthetic efficiency. Measuring plant efficiency, thus health, using commercial fluorometers, such as PAM (pulse-amplitude modulation) devices, presents a challenge, since cost, complexity and the measurement methods make real-time monitoring a difficult proposition. Although such devices are high-precision instruments, they are merely able to provide ‘snapshots’ of small areas. This makes it difficult to understand the health of plants over large areas and over extended periods of time, frequently resulting in actions taken only after significant changes to plants and productivity. One solution would be for a farmer in an area impacted by pollution to acquire multiple of these devices and to employ a workforce dedicated solely to monitoring plant health, but this is costly and inefficient. Another solution would be to simplify the devices with which to measure, and use a multitude of these. Indeed, in this work, we focus on solving this problem, by reducing costs and complexity, and eliminating the need for human input in the measurement process. We propose a system of low-cost chlorophyll fluorescence sensors able to monitor a large number of individual plants at the same time and wirelessly. These sensors have been designed, prototyped and built from the ground up to provide reasonable accuracy, and capacity for discriminating between plants subjected to stress from non-stressed plants. Where our sensor system, the CFY (chlorophyll fluorescence yield) Sensor, lacks in accuracy, it compensates with a multitude of potential simultaneous measurements from an array of sensors within a network. For this reason, the sensor prototype is inherently designed for wireless sensor networks (WSN). Using two species of plants, Clusia hilariana and Paspalum densum, we have built, tested and verified our methodologies and prototype sensors through a series of experiments. Through these, we observed significant results when employed in an emulated sensor network using one sensor on a large number of plants over extended periods of time. Differentiating the stressed group from the control group was possible, in addition to rapid and well before any visible damage had manifested on leaves. We conclude that it is indeed possible to not only detect plant stress using low-cost methods, but also to do so automatically and in real-time, allowing for early-detection of pollution and providing e.g. a farmer enough time to resolve problems before they become irreversible and costly.
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GRASSO, NIVES. "Visibility analyses using 3D urban models generated by low-cost multi-sensor approaches." Doctoral thesis, Politecnico di Torino, 2018. http://hdl.handle.net/11583/2705900.
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The conditions of visibility of a user moving through an outdoor or indoor environment affect his safety. In both environments it is fundamental to guarantee a sufficient visibility in order to avoid possible collisions. In the specific case of urban roads the available sight distance (ASD) is that part of the roadway ahead which is visible to the driver and should be of sufficient length to allow a vehicle to stop before colliding with a stationary object. Unfortunately, the estimation of the ASD is still carried out on 2D maps or digital terrain models (DTM). Furthermore, it is very complicated to estimate the ASD on urban roads due to difficulties in measuring the effects of individual sight obstructions in a context where their density and dynamicity is relatively high. It is obvious that a 3D representation of the infrastructure may offer more flexibility when modeling sight obstructions and in capturing the complexity of the urban context. Different consideration must to be made for indoor environment, in which, in particular for public buildings, it is important that the main escape routes are correctly signalized. In these situations, a large number of people must easily flow even in highly articulated environments. It is necessary to identify the easiest paths to follow in order to ensure a fast and efficient escape route. The ways in which a person is able to move within the environment are strongly influenced by the space he is able to see in front of himself. The indoor geometry of buildings and the position of some objects can limits the visibility, affecting the perception of the paths through which it is possible to navigate. Different methods have been analyzed to identify the visible space from a certain point of view, by linking the user's perception with the surrounding environment. However, many of these studies are aimed at a two-dimensional environment analysis, or do not take into account a possible dynamic configuration of the motion. The aim of this research work is to propose automatic methods for the visibility analysis, indoor and outdoor, that take into account the dynamism of the individual and the environment. Since it is essential to have a 3D model on which to base the analyses, the first part of the research, will be focused on the investigation of rapid and flexible survey methods, capable of adapting to different contexts of interest. Today the geomatics field already offers different solutions and technologies for collecting 3D information of objects or environments at different scales. In recent years, the development of mobile mapping systems (MMS) that integrate active, passive and positioning sensors, has made a substantial increase in applications in the close-range domain. Moreover, the growth of software solutions for the extraction of point clouds from non-metric image sets has obtained great attention; in fact, these systems combine a good quality of results, both from a metric and a qualitative point of view, simplicity in their use and their accessibility, thanks also to the various free and open source solutions. The main issue regarding the existing MMSs is the high cost of these technologies, which limits their use. A goal of this work is related to evaluate the possibility to realize and to use low-cost MMSs as an alternative for obtaining 3D information of urban infrastructure. Here the term MMS is used in its broadest meaning, considering MMSs all those mapping systems that can be mounted on any type of mobile platform (aerial or terrestrial). In particular, low-cost MMSs mounted on a vehicle or bicycle or carried out by a pedestrian (such as backpacks) will be proposed. Today the mass-market offers a wide choice of low-cost sensors for image acquisition and positioning. Among the imaging sensors, it is possible to find webcams, action-cams and other solutions that can capture high-resolution images while maintaining a very small size and weight. However, these sensors are born with different purposes from the photogrammetric one and, therefore, their use must necessarily be preceded by an analysis of their intrinsic characteristics and their performances and limits under different conditions of use. Starting from these assumptions, the characteristics of multiple low-cost imaging sensors (an action-cam Garmin Virb Elite, Logitech HD Pro Webcams C920, Raspberry Pi Camera Modules v2 and a panoramic camera NCTech iSTAR Fusion) and their intrinsic parameters have been evaluated. Subsequently, after the realization of different tools for the management of the sensors, their synchronization in time and the data storage, some tests were performed in an urban environment in order to evaluate the performances of different configurations of low-cost MMSs and the accuracies of the obtainable 3D models. The input data used for the 3D information extraction were video and frames, which were processed through Structure from Motion (Sfm) technique.
The second part of the activities aimed at the development of automatic procedures to perform visibility analysis exploiting the obtained 3D model of the environment. Different tools for the visibility analysis and the estimation of the ASD from a driver’s point of view were compiled and tested. These approaches aimed at identifying all the objects that obstruct the sight of the driver along the road infrastructure. The visibility analyses were performed through ArcGIS and Matlab® tools using the Line of Sight (LoS) approach, and taking into account the dynamicity of the movement. Finally, a procedure for quantitatively assessing the complexity of a known path to follow in emergency cases inside of public buildings was proposed. The methodology combines the use of isovists and visibility graphs techniques and allows to extract numerical descriptors of the environment.
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Ozyalcin, Anil E. "SOLITONS: A COMPACT, LOW-COST, AND WIRELESS BODY MOTION CAPTURE SYSTEM." The Ohio State University, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=osu1437440750.
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Eydgahi, Hoda. "Design and evaluation of iCalm : a novel, wrist-worn, low-power, low-cost, wireless physiological sensor module." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/44690.
Повний текст джерелаАнотація:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 151-156).
The impracticality of the ambulatory electrocardiogram for long-term physiological monitoring has lead to the development of many new, compact sensors that have been designed with form factor and user comfort in mind. Nevertheless, there currently is no single sensor module that would be ideal to use for continuous, long-term monitoring. The sensors tend to either lack wireless capabilities, have a short battery life, or are financially unfeasible. After conducting a quick survey of recently developed sensors, we propose the design of iCalm: a novel, wrist-worn, low-power, low-cost, and wireless physiological sensor module. Its performance is compared against an FDA-approved platform through numerous experiments, including a few user studies. The iCalm skin conductance sensor greatly reduced noise due to motion and pressure artifacts; the iCalm heart rate sensor performed similar to the FDA-approved sensor. In addition, all of the participants in the experiments preferred the iCalm to the FDA-approved comparison sensors we tested. With iCalm, we hope to enable comfortable, long-term monitoring of the autonomic nervous system physiology and improve upon the current commercial sensors on the market.
by Hoda Eydgahi.
S.M.
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TEPPATI, LOSE' LORENZO. "Geomatics support to the metric documentation of the archaeological heritage. Tests and validations on the use of low-cost, rapid, image-based sensors and systems." Doctoral thesis, Politecnico di Torino, 2019. http://hdl.handle.net/11583/2735515.
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Aquilanti, Claudia. "Sensor Fusion of GPS and speed information for low-cost automotive positioning and navigation." Thesis, KTH, Signalbehandling, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-53767.
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Global navigation satellite systems, such as the Global Positioning System (GPS) are nowadays widespread in the consumer and professional fields. To guarantee the desired accuracy, availability, integrity and robustness performance, it is necessary to add to GPS receivers aiding systems, like extra sensors, which can be expensive. In order to reduce the expenses, a low-cost alternative aiding system is here presented. The main idea is to extract the information needed to support the GPS services from an easily measurable signal as the one provided by the power supply of a car. This signal has a frequency component related to the rpm speed of the engine, thus it can be used to estimate the speed, and related states, when the GPS service is unavailable for some reason. Unfortunately, the frequency component isequal to the speed measured by the GPS up to a scale factor dependent on the gear engaged, so it is necessary to estimate over time these scale factors in order to use the information. In this thesis project we implemented an off-line system which leads to the estimation over time of the scale factors. A sensor fusion solution has been used: training data consisting only of speed measurement provided by the GPS and measurements of the signal of interest are processed through a bench of five Kalman Filters (one for each gear) which leads to the estimation of the scale factors. Three measurement campaigns with three different cars have been conducted in order to collect an exhaustive amount of datasets necessary to calibrate and then validate the system.
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Puehn, Christian G. "Development of a Low-Cost Social Robot for Personalized Human-Robot Interaction." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1427889195.
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Kuhn, Tara. "Application of low-cost sensing technologies towards advancement in atmospheric science and citizen engagement." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/208420/1/Tara_Kuhn_Thesis.pdf.
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This project contributed towards advancement of low-cost air quality sensor networks. Two sensor networks were deployed with the aid of local communities, and data were collected via the 3G network to a cloud-based server. Data analysis involved using least square regression lines to determine temporal changes in air quality, and students t-tests to determine how air quality differed over space. The thesis investigated air quality results of two campaigns and evaluated the success of installing these networks with community aid. The methods demonstrated the robustness of a new low-cost sensor network and quantified how cruise ships deteriorate local air quality.
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Grobler, Andries Johannes. "A low cost eddy current displacement sensor for active magnetic bearings / by Andries J. Grobler." Thesis, North-West University, 2008. http://hdl.handle.net/10394/2627.
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The McTronX research group of the North-West University is involved in active magnetic bearing (AMB) research. An AMB is a mechatronic system that levitates a rotating axis with electromagnetic forces. The group has successfully implemented radial and axial AMBs as well as a complete flywheel energy storage system operating at 22 000 rpm. Research is also done on using the actuator voltage and current to derive rotor position, also known as self-sensing, but these methods have not been perfected. Position measurement is very important in AMBs, since it is the main control variable. The literature indicates that the eddy current phenomenon is well suited for displacement measurement, since it is relatively noise immune and insensitive to process medium when a nonmagnetic and non-conductive substance is used. Printed circuit board (PCB) sensors must be considered when low cost is a requirement. The goal of this project is to design, simulate, manufacture and test a PCB based, low cost eddy current displacement sensor for AMBs. This project will focus on the sensor (probe) that converts the physical rotor movement to an electric signal. An evaluation platform, used to test the PCB sensor, is also designed and manufactured as part of this project.
The first step in the sensor design is to establish a suitable software model. A finite element
method (FEM) software package, Comsol® , is used to realise a FEM model of the sensor. This FEM model is used to simulate sensor behaviour in various configurations. The trends found in the FEM model results are used to compile a design flow diagram. This diagram is illustrated by applying it to single, double- and five-layer designs. The single- and double-layer sensors are manufactured and tested to validate the accuracy of the FEM model and design flow diagram. Close correlation between the practical and predicted results is found for the single- and double layer sensors. The sensitivity and working point rms voltage correlated exceptionally well for both sensors. Linearity does not correlate as closely due to the evaluation platform and circuitry but is still within acceptable limits when compared to other displacement sensors used in AMBs. This project laid the foundation for PCB sensor design in the McTronX group. A comparison between the different sensors showed that the double-layer sensor is the best choice in terms of cost and performance. It is concluded that the PCB displacement sensor presented in this dissertation is a viable low cost option for displacement measurement in AMBs.The McTronX research group of the North-West University is involved in active magnetic bearing (AMB) research. An AMB is a mechatronic system that levitates a rotating axis with electromagnetic forces. The group has successfully implemented radial and axial AMBs as well as a complete flywheel energy storage system operating at 22 000 rpm. Research is also done on using the actuator voltage and current to derive rotor position, also known as self-sensing, but these methods have not been perfected. Position measurement is very important in AMBs, since it is the main control variable. The literature indicates that the eddy current phenomenon is well suited for displacement measurement, since it is relatively noise immune and insensitive to process medium when a nonmagnetic and non-conductive substance is used. Printed circuit board (PCB) sensors must be considered when low cost is a requirement. The goal of this project is to design, simulate, manufacture and test a PCB based, low cost eddy current is placement sensor for AMBs. This project will focus on the sensor (probe) that converts the physical rotor movement to an electric signal. An evaluation platform, used to test the PCB sensor, is also designed and manufactured as part of this project. The first step in the sensor design is to establish a suitable software model. A finite element method (FEM) software package, Comsol, is used to realise a FEM model of the sensor. This FEM model is used to simulate sensor behaviour in various configurations. The trends found in the FEM model results are used to compile a design flow diagram. This diagram is illustrated by applying it to single, double- and five-layer designs. The single- and double-layer sensors are manufactured and tested to validate the accuracy of the FEM model and design flow diagram. Close correlation between the practical and predicted results is found for the single- and double layer sensors. The sensitivity and working point rms voltage correlated exceptionally well for both sensors. Linearity does not correlate as closely due to the evaluation platform and circuitry but is still within acceptable limits when compared to other displacement sensors used in AMBs. This project laid the foundation for PCB sensor design in the McTronX group. A comparison between the different sensors showed that the double-layer sensor is the best choice in terms of cost and performance. It is concluded that the PCB displacement sensor presented in this dissertation is a viable low cost option for displacement measurement in AMBs.
Thesis (M.Ing. (Electrical Engineering)--North-West University, Potchefstroom Campus, 2008.
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Smithers, Breana Gray. "Evaluating the Pulse Sensor as a Low-Cost and Portable Measurement of Blood Pulse Waveform." Thesis, University of North Texas, 2016. https://digital.library.unt.edu/ark:/67531/metadc849682/.
Повний текст джерелаАнотація:
This study was aimed at determining whether the digital volume pulse waveform using the Pulse Sensor can be used to extract features related to arterial compliance. The Pulse Sensor, a low-cost photoplethysmograph, measures green light reflection in the finger and generates output, which is indicative of blood flow and can be read by the low-cost Arduino UNO™. The Pulse Sensor code was modified to increase the sampling frequency and to capture the data in a file, which is subsequently used for waveform analysis using programs written in the R system. Waveforms were obtained using the Pulse Sensor during two 30-s periods of seated rest, in each of 44 participants, who were between the ages of 20 and 80 years. For each cardiac cycle, the first four derivatives of the waveform were calculated and low-pass filtered by convolution before every differentiation step. The program was written to extract 19 features from the pulse waveform and its derivatives. These features were selected from those that have been reported to relate to the physiopathology of hemodynamics. Results indicate that subtle features of the pulse waveform can be calculated from the fourth derivative. Feature misidentification occurred in cases of saturation or low voltage and resulted in outliers; therefore, trimmed means of the features were calculated by automatically discarding the outliers. There was a high efficiency of extraction for most features. Significant relationships were found between several of the features and age, and systolic, diastolic, and mean arterial blood pressure, suggesting that these features might be employed to predict arterial compliance. Further improvements in experimental design could lead to a more detailed evaluation of the Pulse Sensor with respect to its capability to predict factors related to arterial compliance.
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Liu, Xiaoting. "Developing a scientific basis for utilisation of low-cost sensing technologies towards quantitative assessments of air pollution and its sources." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/212115/1/Xiaoting_Liu_Thesis.pdf.
Повний текст джерелаАнотація:
This thesis develops a scientific basis for the use of low-cost sensing technologies for quantitative assessment of air pollution and its sources. It has extensively identified the capabilities and limitations of low-cost sensors in laboratory and field environments. Essentially, it has demonstrated that low-cost sensors are capable of monitoring air quality with a high degree of accuracy in different locations (e.g., highly polluted areas) and for different purposes (e.g., citizen science projects for raising environmental awareness).
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Rida, Amin H. "Conductive inkjet printed antennas on flexible low-cost paper-based substrates for RFID and WSN applications." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28083.
Повний текст джерелаАнотація:
Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009.Committee Chair: Dr. Manos Tentzeris; Committee Member: Dr. Gregory Durgin; Committee Member: Dr. Joy Laskar.
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Li, Chen. "A simple and low cost anti-lock braking system control method using in-wheel force sensor and wheel angular speed sensor." Thesis, Coventry University, 2017. http://curve.coventry.ac.uk/open/items/aebcb301-fec5-4684-945c-020817157509/1.
Повний текст джерелаАнотація:
The ABS (Anti-lock Braking System) is an active safety system that is designed for emergency braking situations. In an emergency braking scenario, the ABS instructs the disk-pad braking force to achieve the maximum available tyre-road braking force without locking the wheels. The maximum available tyre-road braking force helps to achieve the optimal braking distance, while the rotating wheels allow the vehicle to retain directional control capability, which allows the driver to avoid dangerous obstacles during an emergency braking scenario. This research has delivered a new and novel approach to ABS design, which could be developed at a low cost in a way which will benefit specialist and niche vehicle manufacturers alike. The proposed ABS control method combines the control logic from both theory-based ABS and commercialised ABS. Therefore, it is more practical compared to the theory-based ABS and less complex compared to a commercialised ABS. The control method only has two control phases with simple decrease, hold, and increase control actions. The proposed ABS control method uses representable tyre-road braking force data from an in-wheel-hub force measurement sensor as well as wheel angular acceleration data from a wheel angular speed sensor as control references. It uses the detected peak tyre-road braking force and its relative predefined drop percentage as control activation and control phase alternation triggers. It uses wheel angular acceleration to identify the control phase and implement the correct control actions. Zero wheel angular acceleration is used to trigger the hold control action in the first control phase, while wheel angular acceleration is used as an aid to increase the accuracy of the in-wheel-hub force sensor. An ADAMS full vehicle model based on a Subaru Impreza and a Simulink ABS control logic model have been used to establish a co-simulation environment to test the performance of the proposed ABS control method using high, low friction and split-mu road surfaces. The co-simulation results demonstrate that the proposed novel ABS control method satisfies the ABS control target, and its control results are similar to commercialised ABS.
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Khosravani, Ali Mohammad [Verfasser], and Dieter [Akademischer Betreuer] Fritsch. "Automatic modeling of building interiors using low-cost sensor systems / Ali Mohammad Khosravani. Betreuer: Dieter Fritsch." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2016. http://d-nb.info/1088404243/34.
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Riedesel, Philipp. "Tilt sensing with low-cost inertial measurement units (IMUs) : Sensor calibration, accuracy specifications and application range." Thesis, Högskolan i Gävle, Samhällsbyggnad, GIS, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-22497.
Повний текст джерелаАнотація:
Many surveying engineering applications require the knowledge of the orientation parameters of instruments. One can use inertial measurement units (IMUs) to determine that. IMUs are combinations of several inertial sensors and comprise at least an accelerometer and a gyroscope. Therefore, they can detect accelerations and angular rates in a three-dimensional space. As micro-electro-mechanical systems, the sensors are increasingly getting smaller and lighter, but without being reduced in their accuracy. The smaller size facilitates diverse placing of the sensors, which allows a variety of uses. Moreover, several low-cost IMUs have been devised since the development of single-board computers. The main objectives of this work are to determine tilts using a low-cost IMU, and the accuracy of the sensor. Furthermore, it studies general IMU applications in surveying engineering, and examines whether low-cost versions are applicable. To fulfil the objectives, the study was based on a selected low-cost IMU. Two programs were developed as part of this work. One was to control the sensor and the other, to calculate the tilts and analyse the data. The IMU was mounted in front of the objective of the total station and aligned in different reference orientations. All measurements were performed under controlled thermal conditions. Thereby, it was ensured that no falsifications could appear due to ambient temperature influences. As a first step, the sensor calibration process was completed. It helped determine the signal offset parameter and their time-dependent change. The calibration was done using two present methods, the six-position and the multi-position methods. The calibrated IMU helped determine the tilts. This was done in the case of the accelerometer via trigonometric functions, which allowed an absolute orientation statement. In contrast, the gyroscope provided relative orientation with the multiplication of the detected angular variance and the time that passed. After that, a target-actual comparison with the reference information of the total station helped determine the external accuracy of the tilt from the IMU. Moreover, multiple measurements could give a statement of the internal accuracy. Finally, the Kalman Filter was added to smooth out the sensor data and combine it in real-time. The calibration methods showed similar results, and it was striking that the sensors did not show the expected drifts. The reason could be related to a pre-calibration by the manufacturer. On the one hand, the used IMU showed differences in the total station alignments in the order of 0.798° for the accelerometer and up to 4.3° for the gyroscope with the calibrated data. On the other, the differences in repeated measurements were at 0.024° for the accelerometer and 0.5° for the gyroscope. It was figured out different possible applications of IMUs in surveying engineering. Among other things, these included orientation monitoring of sensor platforms or the determination of the external orientation of unmanned aerial systems. For these applications, the usability depends on the achievable accuracy. In the case of the IMU chosen in this study, the proven accuracy is too inaccurate for these applications. There is a need for further investigation because the use of another sensor type may rectify the insufficient accuracy problem. Moreover, to achieve better accuracies and to make it possible to use the IMU in different ambient temperatures, the temperature influence must be determined.
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Wanjau, R. W. "The design and development of an organic comparator for use in low cost smart sensor systems." Thesis, University of Liverpool, 2017. http://livrepository.liverpool.ac.uk/3019225/.
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Ferdoush, Sheikh Mohammad. "A Low-cost Wireless Sensor Network System Using Raspberry Pi and Arduino for Environmental Monitoring Applications." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc500182/.
Повний текст джерелаАнотація:
Sensors are used to convert physical quantity into numerical data. Various types of sensors can be coupled together to make a single node. A distributed array of these nodes can be deployed to collect environmental data by using appropriate sensors. Application of low powered short range radio transceivers as a communication medium between spatially distributed sensor nodes is known as wireless sensor network. In this thesis I build such a network by using Arduino, Raspberry Pi and XBee. My goal was to accomplish a prototype system so that the collected data can be stored and managed both from local and remote locations. The system was targeted for both indoor and outdoor environment. As a part of the development a controlling application was developed to manage the sensor nodes, wireless transmission, to collect and store data using a database management service. Raspberry Pi was used as base station and webserver. Few web based application was developed for configuring the network, real time monitoring, and database management. Whole system functions as a single entity. The use of open source hardware and software made it possible to keep the cost of the system low. The successful development of the system can be considered as a prototype which needs to be expanded for large scale environmental monitoring applications.
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Ramadoss, Lalitha Hung John Y. "Statistical analysis of time delays in USB type sensor interfaces on Windows-based low cost controllers." Auburn, Ala, 2008. http://hdl.handle.net/10415/1450.
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Sadler, Jeffrey Michael. "Hydrologic Data Sharing Using Open Source Software and Low-Cost Electronics." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/4425.
Повний текст джерелаАнотація:
While it is generally accepted that environmental data are critical to understanding environmental phenomena, there are yet improvements to be made in their consistent collection, curation, and sharing. This thesis describes two research efforts to improve two different aspects of hydrologic data collection and management. First described is a recipe for the design, development, and deployment of a low-cost environmental data logging and transmission system for environmental sensors and its connection to an open source data-sharing network. The hardware is built using several low-cost, open-source, mass-produced components. The system automatically ingests data into HydroServer, a standards-based server in the open source Hydrologic Information System (HIS) created by the Consortium of Universities for the Advancement of Hydrologic Sciences Inc (CUAHSI). A recipe for building the system is provided along with several test deployment results. Second, a connection between HydroServer and HydroShare is described. While the CUAHSI HIS system is intended to empower the hydrologic sciences community with better data storage and distribution, it lacks support for the kind of “Web 2.0” collaboration and social-networking capabilities that are increasing scientific discovery in other fields. The design, development, and testing of a software system that integrates CUAHSI HIS with the HydroShare social hydrology architecture is presented. The resulting system supports efficient archive, discovery, and retrieval of data, extensive creator and science metadata, assignment of a persistent digital identifier such as a Digital Object Identifier (DOI), scientific discussion and collaboration around the data and other basic social-networking features. In this system, HydroShare provides functionality for social interaction and collaboration while the existing HIS provides the distributed data management and web services framework. The system is expected to enable scientists, for the first time, to access and share both national- and research lab-scale hydrologic time series in a standards-based web services architecture combined with a social network developed specifically for the hydrologic sciences.These two research projects address and provide a solution for significant challenges in the automatic collection, curation, and feature-rich sharing of hydrologic data.
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Ashraf, Shahrukh. "Development of a Low-Cost Solution for the Navigation of UAVs in GPS-DeniedEnvironment." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1470181376.
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Taylor, Michael D. "Calibration and Characterization of Low-Cost Fine Particulate Monitors and their Effect on Individual Empowerment." Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/932.
Повний текст джерелаАнотація:
Air quality has long been a major health concern for citizens around the world, and increased levels of exposure to fine particulate matter (PM2:5) has been definitively linked to serious health effects such as cardiovascular disease, respiratory illness, and increased mortality. PM2:5 is one of six attainment criteria pollutants used by the EPA, and is similarly regulated by many other governments worldwide. Unfortunately, the high cost and complexity of most current PM2:5 monitors results in a lack of detailed spatial and temporal resolution, which means that concerned individuals have little insight into their personal exposure levels. This is especially true regarding hyper-local variations and short-term pollution events associated with industrial activity, heavy fossil fuel use, or indoor activity such as cooking. Advances in sensor miniaturization, decreased fabrication costs, and rapidly expanding data connectivity have encouraged the development of small, inexpensive devices capable of estimating PM2:5 concentrations. This new class of sensors opens up new possibilities for personal exposure monitoring. It also creates new challenges related to calibrating and characterizing inexpensively manufactured sensors to provide the level of precision and accuracy needed to yield actionable information without significantly increasing device cost. This thesis addresses the following two primary questions: 1. Can an inexpensive air quality monitor based on mass-manufactured dust sensors be calibrated efficiently in order to achieve inter-device agreement in addition to agreement with professional and federally-endorsed particle monitors? 2. Can an inexpensive air quality monitor increase the confidence and capacity of individuals to understand and control their indoor air quality? In the following thesis, we describe the development of the Speck fine particulate monitor. The Speck processes data from a low-cost dust sensor using a Kalman filter with a piecewise sensing model. We have optimized the parameters for the algorithm through short-term co-location tests with professional HHPC-6 particle counters, and verified typical correlations between the Speck and HHPC-6 units of r2 > 0:90. To account for variations in sensitivity, we have developed a calibration procedure whereby fine particles are aerosolized within an open room or closed calibration chamber. This allows us to produce Specks for commercial distribution as well as the experiments presented herein. Drawing from previous pilot studies, we have distributed low-cost monitors through local library systems and community groups. Pre-deployment and post-deployment surveys characterize user perception of personal exposure and the effect of a low-cost fine particulate monitor on empowerment.
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Kartmann, Sabrina [Verfasser], and Roland [Akademischer Betreuer] Zengerle. "Normally-closed dispensing valve and in-line pressure and flow sensor fabricated in low-cost polymer technology." Freiburg : Universität, 2021. http://d-nb.info/1237617987/34.
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Kiobia, Denis Olgen. "Design and Development of a Low-cost Acoustic Device to Detect Pest Infestation in Stored Maize." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/56588.
Повний текст джерелаАнотація:
Insect damage in stored maize is one of the major post-harvest losses occurring in developing countries, especially in sub-Saharan Africa. To reduce economic losses, separation of infested grains from clean ones is critical and requires detection of infestation in stored grains. This study aimed at developing a rapid non-destructive detection system with three goals; - the first goal was to investigate the acoustic behavior of internally feeding S. zeamais (Coleoptera: Curculionidae) in maize. The pests were monitored for peak activity and signal amplitudes. The study was performed in the morning, afternoon and night times for three consecutive days with an ultrasonic probe attached to acoustic emission detector. The average number of peaks above threshold in the morning, afternoon and night was significantly different and were 60, 2 and 31 counts/s, respectively (P-value < 0.01). The average maximum amplitude was also different: 2.5, 1 and 1.8V for morning, afternoon and night sessions, respectively. The signal frequencies ranged between 1 and 15 kHz with a peak around 7 kHz. The second goal was to design and develop an inexpensive acoustic device for the detection of S. zeamais in the stored maize. This device included a microphone, signal conditioning circuit and a microcontroller. The third goal was to test the prototype in both clean and infested maize. The device could be manufactured for $55 or less. The device has a noise level below 0.2V in clean maize, infestation amplitude up to 1V and about 93.3% correct detection performance in infected maize.Master of Science
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Sundblad, Graziella. "Building a low-cost IoT sensor system that recognizes behavioral patterns for collaborative learning - A Proof of Concept." Thesis, Malmö universitet, Institutionen för datavetenskap och medieteknik (DVMT), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-44351.
Повний текст джерелаАнотація:
Since the advent of the Internet, we have been observing a fast-paced development within the computing world. One of the major innovations in recent years is the “Internet of Things”, which brings interconnectedness between devices and humans to unprecedented heights. This technological breakthrough enabled the emergence of a new sub-field within Learning Analytics, Multimodal Learning Analytics, which makes use of several types of data sources to study learning-related processes. As computers and sensors become increasingly cheaper and more accessible, research within this new sub-field grows, yet some gaps remain unexplored. Additionally, there is a research bias toward computer-assisted learning environments, rather than physical ones. At the same time, the current labor market is highly competitive, and possessing profession-related skills is not sufficient to land a job. Besides these skills, there is an increasing demand for social skills, such as communication, teamwork, and collaboration. However, there is a gap between the skills that are trained in an academic setting and the ones that are required by the labor market. Having this background in mind, this work aims at designing and evaluating an IoT sensor system capable of tracking patterns observed under social interactions within a group, and more specifically, in terms of the distance between group members while solving a task. Another important aspect of this study is the system's cost-effectiveness so that it can be employed in a scalable and sustainable manner. To achieve this goal, a multimethodological approach for Design Science Research was adopted, which implied the combination of several methods such as sketching, prototyping, and testing. As a result, this study contributes both to the research area of Multimodal Learning Analytics, and to educational practices.
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Leccadito, Matthew. "A Kalman Filter Based Attitude Heading Reference System Using a Low Cost Inertial Measurement Unit." VCU Scholars Compass, 2013. http://scholarscompass.vcu.edu/etd/3189.
Повний текст джерелаАнотація:
This paper describes, the development of a sensor fusion algorithm-based Kalman lter ar- chitecture, in combination with a low cost Inertial Measurement Unit (IMU) for an Attitude Heading Reference System (AHRS). A low cost IMU takes advantage of the use of MEMS technology enabling cheap, compact, low grade sensors. The use of low cost IMUs is primar- ily targeted towards Unmanned Aerial Vehicle (UAV) applications due to the requirements for small package size, light weight, and low energy consumption. The high dynamics nature of smaller airframes, coupled with the typical vibration induced noise of UAVs require an e cient, reliable, and robust AHRS for vehicle control. To eliminate the singularities at 90 on the pitch and roll axes, and to keep the computational e ciency high, quaternions are used for state attitude representation.
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Ozturk, Salih Baris. "Modelling, simulation and analysis of low-cost direct torque control of PMSM using hall-effect sensors." Thesis, Texas A&M University, 2005. http://hdl.handle.net/1969.1/4905.
Повний текст джерелаАнотація:
This thesis focuses on the development of a novel Direct Torque Control (DTC) scheme for permanent magnet (PM) synchronous motors (surface and interior types) in the constant torque region with the help of cost-effective hall-effect sensors. This method requires no DC-link sensing, which is a mandatory matter in the conventional DTC drives, therefore it reduces the cost of a conventional DTC of a permanent magnet (PM) synchronous motor and also removes common problems including; resistance change effect, low speed and integration drift. Conventional DTC drives require at least one DC-link voltage sensor (or two on the motor terminals) and two current sensors because of the necessary estimation of position, speed, torque, and stator flux in the stationary reference frame. Unlike the conventional DTC drive, the proposed method uses the rotor reference frame because the rotor position is provided by the three hall-effect sensors and does not require expensive voltage sensors. Moreover, the proposed algorithm takes the acceleration and deceleration of the motor and torque disturbances into account to improve the speed and torque responses. The basic theory of operation for the proposed topology is presented. A mathematical model for the proposed DTC of the PMSM topology is developed. A simulation program written in MATLAB/SIMULINKî is used to verify the basic operation (performance) of the proposed topology. The mathematical model is capable of simulating the steady-state, as well as dynamic response even under heavy load conditions (e.g. transient load torque at ramp up). It is believed that the proposed system offers a reliable and low-cost solution for the emerging market of DTC for PMSM drives. Finally the proposed drive, considering the constant torque region operation, is applied to the agitation part of a laundry washing machine (operating in constant torque region) for speed performance comparison with the current low-cost agitation cycle speed control technique used by washing machine companies around the world.
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Sendra, Compte Sandra. "Deployment of Efficient Wireless Sensor Nodes for Monitoring in Rural, Indoor and Underwater Environments." Doctoral thesis, Editorial Universitat Politècnica de València, 2013. http://hdl.handle.net/10251/32279.
Повний текст джерелаАнотація:
Existen muchos trabajos relacionados con el diseño y desarrollo de nodos sensores, donde se presentan gran variedad de aplicaciones. Las redes de sensores inalámbricos pueden facilitarnos y mejorar algunos aspectos de nuestra vida diaria. Es fácil, pensar que si este tipo de dispositivo es tan beneficioso para nosotros y para el entorno donde vivimos, su precio debería ser relativamente barato. Pero podemos comprobar que esto no es así. ¿Por qué estos dispositivos son tan caros? ¿Sería posible desarrollar dispositivos con las mismas capacidades y precios más económicos? ¿Cómo puedo fabricar mis nodos sensores de bajo coste?
Esta tesis responde a estas preguntas y muestra algunas de las muchas aplicaciones que los nodos sensores pueden tener. En esta tesis hemos propuesto (e implementado en algunos casos) el desarrollo de nodos sensores para la monitorización del medio, a partir de dispositivos de bajo coste. Para la implementación de un nodo sensor, y en definitiva la red que une a todos estos nodos, es importante conocer el medio donde trabajarán. A lo largo de este documento se presentan las investigaciones llevadas a cabo para el desarrollo de sensores en tres ámbitos de aplicación.
En el primero de ellos, se desarrollan dispositivos multisenores para la monitorización del medio. La aplicación de las redes de sensores inalámbricas al medio natural, precisa un estudio de cómo se ven afectadas las señales, en función de la distancia, vegetación, humedad del ambiente, etc. Focalizamos nuestros desarrollos en la verificación de incendios en zonas rurales y en el control de plagas en viñedos donde la detección precoz de estos eventos genera elevados ahorros económicos. También proponemos el desarrollo de una red de collares sensores para ganado domestico, que nos ayudará a reducir y prevenir en muchos casos, los ataques de lobos y hurtos de crías. Por último, dentro de este grupo, presentamos una red permite detectar anomalía de los materiales en edificios y red de sensores que nos permite monitorizar las personas mayores o deficientes, que se mueven junto con un grupo, en una excursión o actividad.
El segundo grupo de aplicaciones, hace referencia a la monitorización de espacios en entornos de interior. Para ello hemos analizado el comportamiento de las señales inalámbricas en diferentes escenarios. Los resultados, nos han permitido extraer un nuevo método de diseño de las redes inalámbricas en interiores. Nuestro método, permite definir la mejor ubicación de los dispositivos de red y nodos sensores en interiores con un ahorro en el número de sensores del 15%.
Por último, se presenta el estudio sobre las comunicaciones subacuáticas basadas en las ondas electromagnéticas donde analizamos la dependencia de las comunicaciones subacuáticas en agua dulce en función de la frecuencia, temperatura, tasas de transferencia de datos y modulación.
Relacionado con el medio subacuático, presentamos 2 propuestas. La primera de ellas hace referencia a la implementación de una red de sensores para granjas marinas que nos permite reducir la cantidad de residuos depositados en el lecho marino y reducir el porcentaje de comida desperdiciada. La segunda propuesta es el desarrollo de dos sensores oceanográficos que nos permitirían controlar la cantidad de comida y heces depositadas en el suelo y controlar la turbidez del agua de manera muy simple y económica
Todos estos desarrollos y propuestas, han estado precedidos por un exhaustivo estudio sobre los problemas energéticos que las redes de sensores inalámbricas presentan y las técnicas que pueden emplearse, para prolongar la vida útil de la red y mejorar su estabilidad.There are many works related to the design and development of sensor nodes which present several applications. Wireless sensor networks can facilitate and improve some aspects of our daily lives. It is easy to think that if this type of device is so beneficial to us and to our environment, its price should be relatively cheap. But we can see that this is not true. Why these devices are so expensive? Would it be possible to develop devices with the same capabilities and lower prices? How can I make my low-cost sensor nodes? This dissertation answers these questions and shows some of the many applications that sensor nodes may have. In this dissertation, we propose (and implement in some cases) the development of sensor nodes for environmental monitoring, from low-cost devices. For the implementation of a sensor node and network which joins all these nodes, it is important to know the environment where they will work. Throughout this dissertation, we present the research carried out for the development of sensors in three main application areas. In the first of these areas, we present multisensor devices developed for environmental monitoring. The application of wireless sensor networks to the environment requires a study of how signals are affected depending on the distance, vegetation, ambient humidity, etc. We focus our developments on the fire detection in rural areas and on the control of pests in vineyards where the early detection of these events generates high economic savings. We also propose the development of a sensor network which will help us to reduce and prevent wolves¿ attacks and theft in livestock. Finally, within this group, we present a network to detect material anomalies in building and a sensor network which allows us to monitor the elderly or disabled people who move along with a group on a tour or activity. The second group of applications is related to the monitoring of spaces in indoor environments. For this, we analyze the behavior of wireless signals in different scenarios. These results allowed us to extract a new method for designing wireless networks in indoor environments. Our method allows defining the best location of network devices and sensor nodes indoors saving 15% of the sensors needed. Finally, we present a study on underwater freshwater communications based on electromagnetic waves, where we analyze the dependency of underwater communications as a function of working frequency, temperature, data transfer rates and modulation. Related to underwater environment, we present two proposals. First one refers to the implementation of a sensor network for marine farms which allows us to reduce the amount of waste deposited on the seabed and reduce the percentage of wasted food. The second proposal is the development of two oceanographic sensors which allow us to control the amount of food and feces deposited in seabed and the water turbidity control in a very simple and inexpensive way. All these developments and proposals have been preceded by a comprehensive study on the energy problems in wireless sensor networks. We have also presented several techniques which can be used to prolong the network lifetime and improve its stability.
Sendra Compte, S. (2013). Deployment of Efficient Wireless Sensor Nodes for Monitoring in Rural, Indoor and Underwater Environments [Tesis doctoral]. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/32279
Alfresco
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Buaes, Alexandre Greff. "A low cost one-camera optical tracking system for indoor wide-area augmented and virtual reality environments." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2006. http://hdl.handle.net/10183/7138.
Повний текст джерелаАнотація:
O número de aplicações industriais para ambientes de “Realidade Aumentada” (AR) e “Realidade Virtual” (VR) tem crescido de forma significativa nos últimos anos. Sistemas óticos de rastreamento (optical tracking systems) constituem um importante componente dos ambientes de AR/VR. Este trabalho propõe um sistema ótico de rastreamento de baixo custo e com características adequadas para uso profissional. O sistema opera na região espectral do infravermelho para trabalhar com ruído ótico reduzido. Uma câmera de alta velocidade, equipada com filtro para bloqueio da luz visível e com flash infravermelho, transfere imagens de escala de cinza não comprimidas para um PC usual, onde um software de pré-processamento de imagens e o algoritmo PTrack de rastreamento reconhecem um conjunto de marcadores retrorefletivos e extraem a sua posição e orientação em 3D. É feita neste trabalho uma pesquisa abrangente sobre algoritmos de pré-processamento de imagens e de rastreamento. Uma bancada de testes foi construída para a realização de testes de acurácia e precisão. Os resultados mostram que o sistema atinge níveis de exatidão levemente piores, mas ainda comparáveis aos de sistemas profissionais. Devido à sua modularidade, o sistema pode ser expandido através do uso de vários módulos monoculares de rastreamento interligados por um algoritmo de fusão de sensores, de modo a atingir um maior alcance operacional. Uma configuração com dois módulos foi montada e testada, tendo alcançado um desempenho semelhante à configuração de um só módulo.In the last years the number of industrial applications for Augmented Reality (AR) and Virtual Reality (VR) environments has significantly increased. Optical tracking systems are an important component of AR/VR environments. In this work, a low cost optical tracking system with adequate attributes for professional use is proposed. The system works in infrared spectral region to reduce optical noise. A highspeed camera, equipped with daylight blocking filter and infrared flash strobes, transfers uncompressed grayscale images to a regular PC, where image pre-processing software and the PTrack tracking algorithm recognize a set of retro-reflective markers and extract its 3D position and orientation. Included in this work is a comprehensive research on image pre-processing and tracking algorithms. A testbed was built to perform accuracy and precision tests. Results show that the system reaches accuracy and precision levels slightly worse than but still comparable to professional systems. Due to its modularity, the system can be expanded by using several one-camera tracking modules linked by a sensor fusion algorithm, in order to obtain a larger working range. A setup with two modules was built and tested, resulting in performance similar to the stand-alone configuration.
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Paulsen, Trevor H. "Low Cost/ High Precision Flight Dynamics Estimation Using the Square-Root Unscented Kalman Filter." BYU ScholarsArchive, 2009. https://scholarsarchive.byu.edu/etd/1922.
Повний текст джерелаАнотація:
For over a decade, Brigham Young University's Microwave Earth Remote Sensing (MERS) team has been developing SAR systems and SAR processing algorithms. In order to create the most accurate image reconstruction algorithms, detailed aircraft motion data is essential. In 2008, the MERS team purchased a costly inertial measurement unit (IMU) coupled with a high precision global positioning system (GPS) from NovAtel, Inc. In order to lower the cost of obtaining detailed motion measurements, the MERS group decided to build a system that mimics the capability the NovAtel system as closely as possible for a much lower cost. As a first step, the same sensors and a simplified set of flight dynamics are used. This thesis presents a standalone motion sensor recording system (MOTRON), and outlines a method of utilizing the square-root Unscented Kalman filter (SR-UKF) to estimate aircraft flight dynamics, based on recorded flight data, as an alternative to the extended Kalman filter. While the results of the SR-UKF are not as precise as the NovAtel results, they approach the accuracy of the NovAtel system despite the simplified dynamics model.
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Niazi, Ayda. "Real time measurement of oxygen by integrating a Clark sensor with low cost printed circuit board technology and solid electrolyte membrane." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6817/.
Повний текст джерелаАнотація:
A prototype of a miniaturized Clark type electrochemical oxygen sensor integrated with a 3D printed in vitro cell culturing platform is designed and developed for the purpose of monitoring the cellular oxygen consumption by the solution flowing through the cultured cells on the platform. Oxygen respiration indicates a cell's metabolic activity, so by measuring a chemical's oxygen content as it passes through a cell chamber, we can measure that chemical's potential effectiveness. This miniature micro sensor is designed and fabricated on a printed circuit board for the first time and integrated with a solid electrolyte membrane and 3D printed cell culturing platform to ensure robustness, low manufacturing cost and good electrical conductivity for sensing. Hence the sensor is aimed at enabling the pharmaceutical industry to rapidly test chemical products on animal and cancer cells; and has been designed to be low cost and suitable for mass production. The presented oxygen sensor configuration consists of two identical series of working, reference and counter microelectrodes. The solid polymer electrolyte membrane, Nafion (perfluorosulfunic acid membrane, DuPont Company) removed requirement for extra humidification and increased the shelf life of the sensor. The sensitivity of the oxygen sensor was tested in different oxygen concentration in gas and liquid states and was calibrated with measurements from a Portable Multi-Gas analyzer and a dissolved oxygen analyzer. The prototype can detect the small changes in oxygen concentration in the range of 0 to 5 μA current and has a response time of less than 5 seconds.